Targeting proteins to deliver therapeutic or diagnostic reagents

ABSTRACT

The present invention is directed to compositions comprising an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent. In a specific embodiment, the composition is a fusion gene or fusion gene product encoding the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent. In a particular embodiment, the composition is used for methods to treat angiogenesis-related diseases, such as cancer.

This application claims priority to U.S. Provisional Patent Application 60/380,063, filed May 6, 2002, which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention is directed to the fields of cell biology, molecular biology, cancer biology, and medicine. More particularly, the present invention relates to compositions comprising an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, and the use of such compositions in therapeutics and cancer therapy.

BACKGROUND OF THE INVENTION

A growing body of evidence reveals that many diseases ranging from age-related macular degeneration, artherosclerosis, rheumatoid arthritis, to cancer are related to angiogenesis, the formation of new blood vessels (Folkman, 2001). Among these angiogenesis-dependent diseases, cancer is the most targeted disease (Brem, 1999; Ferrara and Alitalo, 1999; Keshet and Ben-Sasson, 1999; Carmeliet and Jain, 2000). There are tens of new therapeutic reagents under development based on the theory of antiangiogenesis. In the seminal publication by Folkman, the growth of tumors in both the primary and metastatic sites relies on angiogenesis to support both nutrients and oxygen to tumors (Folkman, 1971). In the following three decades, it has become increasingly convincing that angiogenesis plays a pivotal role in the malignant phenotype. New blood vessel formation has been demonstrated as a critical prognostic factor as well as a therapeutic target in many tumors.

The understanding that tumor growth and metastasis closely relate to the extent of angiogenesis has prompted research laboratories and pharmaceuticals to develop strategies to inhibit angiogenesis, thereby cutting off the blood supply to tumors (Brem, 1999; Ferrara and Alitalo, 1999; Keshet and Ben-Sasson, 1999; Kerbel, 2001; Risau, 1998; Klohs and Hamby, 1999; Rosen, 2000; Burke and DeNardo, 2001; Taraboletti and Margosio, 2001; Glaspy, 2002). Despite the promise of the scientific rationales and scores of experimental drugs being studied in clinical trials, researchers have yet to see significantly positive results from these studies, given the exciting anticancer effects that were demonstrated in the preclinical animal experiments.

Two of the most followed clinical studies involved two endogenous angiogenesis inhibitors, endostatin and angiostatin. These proteins have been shown to be cancer-angiogenesis specific and have no effects on normal blood vessel growth. They have been shown to inhibit cancer growth in animal studies without significant side effects and induction of drug resistance. (Boehm et al., 1997). However, the results from human cancer clinical trials did not match the stunning outcome from the preclinical test (Thomas et al., 2003; Herbst et al., 2002; Eder et al., 2002). Tumor responses in these trials are extremely rare. If there are tumor responses, the rate of the tumor regression is very slow. In some cases, it took more than one year for a patient to see a tumor regress more than 25%. So far, no rapid tumor shrinkage has been demonstrated in clinical trial using these angiogenesis inhibitors. Although tumor responses were not commonly demonstrated in these clinical studies, these endogenous angiogenesis inhibitors did show a very favorable safety profile.

As opposed to the tumor-specific angiogenesis seen in the animal model, tumor-specific blood vessels have been developed for a considerably longer period of time. Therefore, the blood vessels in human tumors are more mature than those in mice tumors. In some embodiments, it will require a longer time of angiogenesis inhibition for these endogenous inhibitors to block the blood flow to tumor to the extent that apoptosis of cancer cells are triggered. These angiogenesis inhibitors exert their function by inhibiting the growth of cancer cells instead of killing the cancer cells. The mechanism of their effect is so called “cytostatic” instead of “cytotoxic”. As opposed to cytotoxic reagents such as chemotherapy drugs, these cytostatic angiogenesis inhibitors can not efficiently attack well-established tumor blood vessels often seen in late stage tumor. Thus, these reagents so far did not demonstrate dramatic anticancer effect in clinical trials where most of the patients enrolled are in late stage and exhausted most of the available treatments

In contrast to the relatively non-toxic yet less potent anti-angiogenic proteins, described elsewhere herein, various potent therapeutic proteins or polypeptides, and the nucleic acids encoding them, have been used in attempts to treat cancers (not necessarily just kill cancer cells) or were suggested for such use. These include, for example, suicidal proteins, apoptosis-inducing proteins, cytokines, interleukines, TNF family proteins, and nucleic acids encoding them. Specific examples include: GM-CSF, Interferon Alpha, Interferon beta, Interferon gamma, Interleukin-1 Beta, Interleukin-2, Interleukin-4, Interleukin-5, Interleukin-6, Interleukin-8, Interleukin-10, Interleukin-12, Interleukin-13, Interleukin-14, Interleukin-16, Interleukin-18, Interleukin-23, Interleukin-24, Tumor Necrosis Factor SuperFamily member 14, Tumor Necrosis Factor SuperFamily member 13B, Tumor Necrosis Factor Alpha, Tumor Necrosis Factor SuperFamily member 12, Intercellular Adhesion Molecule-1, Lymphocyte Function-Associated antigen-3, Co-Stimulatory Molecule B7-1, Co-Stimulatory Molecule B7-2, FMS-related tyrosine kinase 3 ligand, CD40 Ligand, Surface antigen CD70, T-cell activation cell surface glycoprotein ligand, Co-Stimulatory Molecule OX-40 ligand, TNF-related activation-induced cytokine, Tumor Necrosis Factor SuperFamily member 11, TNF-related activation-induced cytokine, Tumor Necrosis Factor SuperFamily member 11, Cytosine deaminase, HSV Thymidine Kinase, Fas ligand, Caspase 3, TGF-α1, TGF-α2, TRAIL, Bax, Bak, Bik, Bok, Noxa, a Bcl-2 family protein, Granulysin (NKG5), Granzyme A, Granzyme B, and Perforin.

For example, IL2 and Interferon-α (Glaspy, 2002) have been used in the treatment for renal cell carcinoma and melanoma. However, significant systemic toxicity is usually seen in the cancer patients, thereby limiting the increase of dose and their clinical effects. IL12 has demonstrated potent and broad anticancer effects (Trinchieri, 2003). However, unacceptable side effects have manifested in some clinical trials (Leonard et al., 1997), which hamper its promise as an anticancer reagent.

To minimize the systemic side effects of cytokines, such as interleukin, as well as those therapeutic proteins listed in Table 1, many proteins have been used to target these otherwise considerably toxic therapeutic proteins to tumor-specific blood vessel. In addition, small molecules have been also utilized for tumor imaging while coupled to proteins specific for targeting tumor angiogenic blood vessels. Some of these approaches are summarized in Table 1.

TABLE 1 Therapeutic/ Targeting Tool Diagnostic Agent Comments Endostatin 99mTc Small molecule 99mTC was used as imaging (Yang et al., 2002) molecule. The inventors used proteins as fused molecule, which could be utilized in gene therapy without having to purify proteins. antibody fragment IL-12 The targeting antibody fragment is specific to one specific to ED-B of angiogenesis markers, ED-B domain of domain of fibronectin fibronectin. However, it does not possess (Halin et al, 2002) antiangiogenic activity. antibody fragment IL-2 Similar approach as (Hahn et al., 2002) specific to ED-B domain of fibronectin (Carnemolla et al., 2002) angiostatin-endostatin Angiostatin- Two antiangiogenic proteins were fused together (Scappaticci et al., Endostatin and demonstrated better antiangiogenic effect than 2001) single molecule. ThE new fusion protein still cytostatic, but not cytotoxic. VEGF Gelonin VEGF is specific to VEGF receptors, which are (Veenendaal et al., diphtheria expressed abundantly in tumor vasculatures. It can 2002; Arora et al., (Veenendaal trigger the angiogenic pathway. VEGF is not an 1999; Hotz et al., et al., 2002) antiangiogenic protein. 2002) Toxin (Arora et al., 1999; Hotz et al., 2002) antibody B21-2 to truncated form of This approach again uses an antibody specific for target I-A^(d), a marker tissue factor (tTF) tumor blood vessel as targeting tool without of tumor specific intrinsic antiangiogenic property. tTF induces blood vessel thrombosis, thereby blocking blood flow. (Huang et al., 1997)

Additional targeting strategies have involved the preparation of immunotoxins (Kreitman, 1999) by coupling antibodies specific to markers of tumor (CD20 of B-cell lymphoma, Her-2/neu of breast cancers, EGFR of colon, head and neck etc.) or tumor-specific blood vessels (ED-B domain of fibronectin, integrin αvβ3, VEGF receptors, etc.) to therapeutic reagents, such as interleukins, cytokines, gelonin, diphtheria toxin, radio-isotopes, etc. However, most of the immunotoxin strategies have yet to enjoy clinical success, except very few have been approved, such as Zevalin™ (ibritumomab tiuxetan) (IDEC Pharmaceuticals; San Diego, Calif.) and Baxxar (Corixa; Seattle, Wash.).

WO 99/16889 describes fusion proteins having an angiostatin amino acid sequence linked to a second moiety having different or complementary activity. In particular embodiments, the second moiety is selected from endostatin, human type I interferon, thrombospondin, interferon-inducible protein 10 (IP-10) and platelet factor 4. In other particular embodiments, the fusion proteins are used for anti-tumor treatment.

In view of the above, there is a need for compositions and methods that overcome the problems in the art and allow for the treatment of angiogenesis-dependent diseases.

BRIEF SUMMARY OF THE INVENTION

The current invention overcomes the problems listed above and results in compounds and therapies that allow for the diagnosis and treatment of angiogenesis-dependent diseases.

In the context of the invention, angiogenesis inhibitors are coupled to therapeutic or diagnostic agents. In many embodiments, the angiogenesis inhibitors are anti-angiogenesis proteins or polypeptides. Given their affinities to new cancer blood vessels, but not to normal blood vessels, these protein and polypeptides can be used as targeting proteins to deliver therapeutic or diagnostic reagents to the vicinity of diseased cells and/or tissues.

Therapeutic proteins/reagents linked to angiogenesis inhibitors have significantly enhanced therapeutic effects, as compared with angiogenesis inhibitors or therapeutic proteins/reagents used alone. Using angiogenesis inhibitors as a delivery (home-in) protein or agent brings the therapeutic reagents to the vicinity of cancer cells and/or tissues, because the angiogenesis inhibitors associate with and/or bind with angiogenesis-specific disease-specific blood vessels. The therapeutic effects of these therapeutic agents are enhanced as a result of the increased local concentrations.

In addition, angiogenesis inhibitors may also be coupled to diagnostic reagents. For example, they may be coupled to green fluorescent proteins, luciferase, radioisotopes, or combinations thereof. These angiogenesis inhibitor-diagnostic reagent conjugates will facilitate diagnosis of patients.

In broad embodiments, the invention related to compositions comprising an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent. Some preferred aspects of the invention related to fusion proteins comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region and to nucleic acids encoding such fusion proteins. However, in other embodiments, an angiogenesis inhibitor can be chemically cross-linked to a therapeutic or diagnostic agent.

Those of ordinary skill will understand, in view of this specification that any antiangiogenesis protein currently know, or in the future discocere, that allows for the aims of the invention to be achieved, will be of use in the contents of the invention. Specific antiangiogenesis proteins or polypeptides employed in the context of the invention are discussed in greater detail in other portions of this specification. Some specific examples, which are presently preferred, include endostatin, tumstatin, angiostatin, and a soluble portion of VEGF Receptor 2.

Therapeutic agents useful in the context of the invention will be well understood by those of skill in the art in view of this specification. In some cases, the therapeutic agent is a therapeutic protein or polypeptide. However small molecules, chemotherapeutic drugs, toxins, radioactive compounds, and any other form of therapeutic agent that may be employed in the invention to achieve a therapeutic benefit are also within the scope of the invention.

As described in greater detail in other portions of this specification, exemplary therapeutic proteins and polypeptides of the invention include, but are in no way limited to, those of the classes of suicidal proteins, apoptosis-inducing proteins, cytokines, interleukins, and TNF family proteins. Exemplary diagnostic proteins or peptides, include for example, a green fluorescent protein and luciferase. The above are only examples of therapeutic proteins that might be fused with an antiangiogenic sequence. One skilled in the art would appreciate that other therapeutic and diagnostic proteins may be used.

In some preferred embodiments of the invention, the angiogenesis inhibitor is an antiangiogenesis polypeptide, such as described elsewhere in this specification. Some preferred embodiments involve endostatin, tumstatin, angiostatin, or a soluble VEGF Receptor 2, as the antiangiogenesis polypeptide. Some preferred therapeutic embodiments of the invention involve, as a therapeutic protein or polypeptide, an interleukin protein or polypeptide, such as, for example, an interleukin-12, a suicide protein, such as, for example, a cytosine deaminase, or an apoptosis-inducing protein, such as, for example, a native or mutant bik protein. Some preferred diagnostic embodiments of the invention involve, as a diagnostic protein or polypeptide, a green flouresncent protein or luciferase. Some specifically preferred therapeutic embodiments include: endostatin/interleukin-12, angiostatin/interleukin-12, tumstatin/interleukin-12, soluble VEGF Receptor 2/interleukin-12, endostatin/cytosine deaminase, angiostatin/cytosine deaminase, tumstatin/cytosine deaminase, soluble VEGF Receptor 2/cytosine deaminase, endostatin/mutant bik, angiostatin/mutant bik, tumstatin/mutant bik, and soluble VEGF Receptor 2/mutant bik. While some specifically preferred diagnostic embodiments include: endostatin/green flourescent protein, angiostatin/green flourescent protein, tumstatin/green flourescent protein, soluble VEGF Receptor 2/green flourescent protein, endostatin/luciferase, angiostatin/luciferase, tumstatin/luciferase, and soluble VEGF Receptor 2/luciferase.

While the simplest embodiments of the invention relate to one angiogenesis inhibitor coupled to one therapeutic or diagnostic agent, there is no reason why more elaborated compositions may not be constructed according to the invention. For example, it is possible to couple two or more angiogenesis inhibitors to a single therapeutic or diagnostic agent, a single angiogenesis inhibitor to two or more therapeutic or diagnostic agents; or even two or more angiogenesis inhibitors to two or more therapeutic or diagnostic agents. In some cases, multiple angiogenesis inhibitors, therapeutic agents, and/or diagnostic agents coupled in the context of the invention will be the same, for example two endostatin polypeptides coupled to a single interleukin-12 polypeptide. Alternatively, multiple angiogenesis inhibitors, therapeutic agents, and/or diagnostic agents coupled in the context of the invention will be the same, for example one endostatin polypeptide coupled to an interleukin-12 polypeptide and a cytosine deaminase polypeptide. Those of skill will be able to follow the teachings of the specification to make any such embodiments of the invention.

In embodiments of the invention relating to fusion proteins, those skilled in the art would appreciate that, typically, the fusion proteins will be expressed from a nucleic acid sequence encoding an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region. In such nucleic acids, it is possible that the nucleic acid sequence encoding an antiangiogenesis polypeptide region could be placed at either the 5′ or the 3′ end of the nucleic acid sequence encoding the therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region. Furthermore, the invention is not restricted in regard to how nucleic acids encoding these fusion proteins should be constructed into an expression vector. The antiangiogenic nucleic acid and the therapeutic or diagnostic nucleic acid may be constructed into a vector in separate construction steps. Alternatively, they may be first fused, then constructed into an expression vector. The invention also relates to nucleic acids encoding a fusion protein comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region. Such nucleic acids may be comprised in a vector, complexed with a lipid, and/or comprised in a pharmaceutically acceptable excipient.

Some specific embodiments of the invention relating to methods of making fusion proteins and nucleic acids encoding such fusion proteins comprise: obtaining a first nucleic acid encoding a fusion protein comprising an antiangiogenesis polypeptide region or complement thereof; obtaining a second nucleic acid encoding a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region or complement thereof; and using the first nucleic acid and the second nucleic acid to create a nucleic acid encoding a fusion protein comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region. These methods may further comprise testing the nucleic acid encoding the fusion protein for an ability to, under appropriate conditions, express the fusion protein and/or for diagnostic or therapeutic activity. Such methods may also, further comprise administering the nucleic acid encoding the fusion protein to a subject.

In addition to using a fusion protein approach, the therapeutic or diagnostic proteins or small molecule reagents may be cross-linked to an antiangiogenic protein, polypeptide, or peptide using chemical cross-linking reagents. One skilled in the art would know that various cross-linking reagents that are specific for certain amino acid side chains are available from commercial sources. The choice of a particular cross-linking reagent would depend on the proteins (or small molecule therapeutic or diagnostic agents) involved.

With a chemical cross-linking approach, one could practice a method comprising: obtaining an angiogenesis inhibitor; obtaining a therapeutic or diagnostic agent; chemically cross-linking the angiogenesis inhibitor to the therapeutic or diagnostic agent to create an angiogenesis inhibitor coupled to the therapeutic or diagnostic agent. Such a method might further comprise testing the angiogenesis inhibitor coupled to the therapeutic or diagnostic agent for diagnostic or therapeutic activity and/or administering the angiogenesis inhibitor coupled to the therapeutic or diagnostic agent to a subject. In an exemplary embodiment, one could express the antiangiogenic gene product, cross link it with the desired molecule (therapeutic or diagnostic), purify the cross-linked product, and administer the product to patients (such as, for example, for therapeutic purposes or a diagnostic purpose, or both) or to laboratory animals (for research purpose).

Some aspects of the invention relate to methods comprising treating a cell with a composition comprising an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent. The cell may be comprised in a subject, or in the alternative, in cell culture. In some embodiments, the cell is comprised in a test subject, such as a mouse. In other embodiments, the subject is a human.

Preferred aspects of the invention related to methods of treating or diagnosing an angiogenesis-dependent disease, for example, but not limited to cancer, age-related macular degeneration, artherosclerosis, angiofibroma, neovascular glaucoma, arteriovenous malformations, nonunion fractures, arthritis, rheumatoid arthritis, lupus, connective tissue, disorders, Osler-Weber syndrome, psoriasis, corneal graft neovascularization, pyogenic granuloma, delayed wound healing, retrolental fibroplasia, diabetic retinopathy, scleroderma, granulations, hemangioma, trachoma, hemophilic joints, vascular adhesions, hypertrophic scars, multiple sclerosis, restenosis, and obesity. Those of skill in the art will, in the context of the invention, understand the definition of “angiogenesis-dependent disease.” Some particular embodiments relate to the treatment of cancer, for example, but not limited to the cancer is head and neck cancer, ovarian cancer, thyroid cancer, oral cancer, prostate cancer, melanoma, colon cancer, breast cancer, angioma, sarcoma, lung cancer, brain cancer, pancreatic cancer, liver cancer, bladder cancer, gastrointestinal cancer, leukemia, lymphoma, and myeloma. Some embodiments of these methods comprise administering to a subject an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, for example, but not limited to, a fusion protein, comprised in pharmacologically acceptable excipient. Other embodiments, comprise administering to the subject a nucleic acid encoding a fusion protein comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region. In such cases, nucleic acid may comprised in a plasmid, a retroviral vector, an adenoviral vector, an adeno-associated viral vector, or associated with a lipid. Further, the nucleic acid may be dispersed in a pharmacologically acceptable excipient.

Specific aspects of the invention relate to methods of treating or diagnosing cancer comprising: obtaining a fusion protein comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region or a nucleic acid encoding a fusion protein comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region; and administering the fusion protein or nucleic acid encoding the fusion protein to a patient.

Other specific aspects of the invention relate to diagnostic and/or therapeutic kits that comprise a composition, fusion protein, or nucleic acid encoding a fusion protein of the invention in an appropriate container.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings.

FIGS. 1A and 1B show that antiangiogenic-therapeutic/diagnostic fusion protein could be detected. FIG. 1A demonstrates anti-endostatin antibody Western blot of supernatants collected from 293 cells (18 KD endostatin(□), 58 KD endostatin-CD (

), and 93 KD endo-IL12(←)). In FIG. 1B, an ELISA kit (specific for endostatin) was utilized.

FIGS. 2A through 2H show that, in comparison to endostatin, endo-CD fusion protein exhibited similar antiangiogenic effects in endothelial tube (2A-2D) and migration (2E-2H) assays. In FIGS. 2A through 2C, HUVEC cell tube formation was studied, and in FIGS. 2E through 2G, cell migration was studied. In FIGS. 2D and 2H, five fields were viewed; and the respective tubes or migrated cells were counted and averaged.

FIGS. 3A through 3D demonstrate that therapeutic or diagnostic functions of fusion genes could be detected. FIGS. 3A and 3B show an MTT assay. FIG. 3C shows green fluorescent protein expression in 293T cells transfected with Endo-GFP fusion gene. In FIG. 3D, the cell proliferation of NSF60 was studied for stimulation by conditional medium from COS-7 transfected by Endostatin-GM-CSF plasmid.

FIGS. 4A through 4F demonstrate that endostatin-GFP specifically targets to endothelial cells.

FIGS. 5A through 5C show that GFP signal was detected in the vascular wall of B-16 parental tumors. FIG. 5A provides GFP detection in an experimental group utilizing tumor of B-16 endostatin-GFP stable cell lines. FIG. 5B provides GFP detection in contra-lateral tumor to A (from B-16 parental cell lines) in blood vessel wall (

). FIG. 5C shows GFP detection in tumors from bilateral B-16 parental cell lines in a control group.

FIG. 6 shows that stable clone-expressed endostatin-GFP inhibits contra-lateral and local tumor growth. In a control group, all of the tumors were measured and averaged together. The tumors in the experimental group were measured and averaged according to their cell lines (B16 parental melanoma cell line or endostatin-GFP stable clones).

FIGS. 7A through 7C demonstrate that endo-IL12 has a superior anticancer effect compared with IL12 or endostatin alone in different independent animal studies. FIG. 7A provides intratumoral gene therapy against B16F10 tumor. FIG. 7B shows similar intratumoral gene therapy as in FIG. 7A against B16F10 tumor, except original distant tumor was challenged at 2×10⁵ cell. FIG. 7C provides illustration comparing endo-IL12 versus IL12 and endostatin alone.

FIGS. 8A through 8D show superior anticancer effect on distant tumor of fusion proteins expressed by either stable clones or ex vivo transfection. FIG. 8A shows ex vivo treatment of endostatin-CD fusion gene of antiangio-chemotherapy (Endo: endostatin; CD: cytosine deaminase; Endo-CD: fusion gene). FIG. 8B shows that ex vivo treatment of Tum5-IL12 fusion gene of antiangio-immunotherapy showed better tumor inhibitory effect on distant tumor (Tum5: tumstatin antiangiogenic deletion mutant, IL12: interleukin-12, Tum5-IL12: fusion gene). FIG. 8C illustrates distant CT26 colon cancer growths in the presence of the fusion genes. Various genes were injected into CT26 tumor sites distant from the measured tumors, which were not treated with direct injection of genes. In FIG. 8D stable line treatment of endostatin-IL12 against distant tumor is provided.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

As used herein the specification, “a” or “an” may mean one or more. As used herein in the claim(s), when used in conjunction with the word “comprising”, the words “a” or “an” may mean one or more than one. As used herein “another” may mean at least a second or more.

The term “therapeutically effective” as used herein refers to the amount of a compound required to improve some symptom associated with a disease. For example, in the treatment of cancer, a compound that improves the cancer to any degree or arrests any symptom of the cancer would be therapeutically effective. For example, the improvement of the cancer may be inhibition of angiogenesis of a cancer cell and/or tissue, inhibition or retardation of cell growth, facilitation of cell death, or a combination thereof. A therapeutically effective amount of a compound is not required to cure a disease but will provide a treatment for a disease.

This application incorporates by reference herein in its entirety PCT International Application WO 99/16889.

The Present Invention

To provide useful compositions and methods for use in the art of cancer therapy, the inventors exploit endogenous angiogenesis inhibitors, which are tumor vessel-specific. In exemplary embodiments, the inventors construct an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent. In some exemplary embodiments, the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent is a fusion of two components: the antiangiogenic component and the therapeutic (or diagnostic) component. In a specific embodiment, the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent is a fusion gene that encodes a fusion protein comprising the two protein components. Thus, the fusion genes may be generated by connecting coding sequences of both antiangiogenic and therapeutic (or diagnostic) protein, thereby transforming cytostatic antiangiogenic proteins into cytotoxic fusion proteins. In addition, antiangiogenic protein could be also fused with diagnostic proteins, such as green fluorescent protein and luciferase, which could be led by antiangiogenic protein to tumor-specific blood vessels. In the alternative embodiment, the antiangiogenic protein component and the therapeutic or diagnostic protein component are chemically linked by standard means in the art. In exemplary embodiments, fusion gene constructs are generated by fusing the nucleic acid encoding at least one antiangiogenic protein with at least one therapeutic or diagnostic nucleic acid.

Given the affinities of angiogenesis inhibitors to newly formed cancer blood vessels, but not to normal blood vessels, these proteins are used as targeting proteins to deliver therapeutic reagents to the vicinity of cancer cells without expansion of toxicity. Therapeutic proteins/reagents linked to these angiogenesis inhibitor will have significantly enhanced cancer killing and anti-cancer effects as compared with angiogenesis inhibitor or the therapeutic proteins/reagents used alone.

Antiangiogenic Proteins

Any antioangiogenic protein, polypeptide, or peptide may be utilized for the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, such as the exemplary targeting fusion gene products of the present invention. Angiogenic inhibitors (also referred to as antiangiogenic compounds) are those that inhibit, reduce, halt, retard, impede, prevent, deter, slow down, reverse, or hinder angiogenesis. In a specific embodiment, the angiogenesis in a tissue imparts deleterious effects on the tissue in which the blood vessels are generating, such as to a tumor or a retina.

Exemplary embodiments include Angiopoietin-2, Angiostatin, AntiThrombin III (AT3), Amino-terminal fragment of Urokinase, Calreticulin, Endostatin, VEGF Receptor 2 (soluble fragment) (prepared by removal of a transmembrane region), VEGF Receptor 1 (soluble fragment) (prepared by removal of a transmembrane region), Interferon-alpha Inducible Protein 10, the 5 Kringle domains of plasminogen, Kringle-5 domain of plasminogen, Mammary serine protease inhibitor, Monokine-induced by Interferon-gamma, Angiostatic chemokines Fusion Gene, Pigment Epithelium-Derived Factor, C-term hemopexin domain of MMP-2, Platelet Factor 4 (CXCL4), Proliferin-Related Protein, Endothelium-specific receptor tyrosine kinase, Tissue inhibitor of metalloproteinase-1, Tissue inhibitor of metalloproteinase-2, Tissue inhibitor of metalloproteinase-3, Tissue inhibitor of metalloproteinase-4, Troponin I-2 (fast-twitch skeletal muscle), Ser94-Gln471 fragment of Tryptophanyl-tRNA synthetase, Thrombospondin, Tumstatin, or a combination thereof. A skilled artisan recognizes how to obtain the sequences for these proteins, polypeptides, or peptides, and the nucleic acid sequences that encode them, by accessing their publically available sequences in the GenBank database provided by the National Center for Biotechnology Information, using well-known means in the art. Exemplary embodiments of antiangiogenic sequences include (accompanied, where appropriate, with their GenBank sequence): endostatin (AF333247; SEQ ID NO:37); angiostatin (SEQ ID NO:38); tumstatin (AF258351; SEQ ID NO:39) and thrombospondin (M81339; SEQ ID NO:40).

Any of these antiangiogenic nucleic acids, as well as others in the art or identified at a later date and not listed herein, could be delivered as a component of gene therapy reagents against cancer or angiogenesis-dependent diseases as fusions with a therapeutic and/or diagnostic protein, as listed herein or as is well known in the art or that may be identified at a later date. Alternatively, fusion proteins encoded by these fusion nucleic acids, and those not listed herein, could be expressed and purified for protein therapy targeting cancer and other angiogenesis-dependent diseases.

A skilled artisan recognizes that, in some embodiments, an antiangiogenic sequence may provide therapy for the disease and/or may provide diagnostic capability for the disease.

Therapeutic/Diagnostic Proteins

Many compositions of the present invention comprise a therapeutic or diagnostic protein or polypeptide, or nucleic acids encoding therefore. Any such therapeutic or diagnostic protein or polypeptide, or nucleic acid encoding such may be used in the present invention, whether presently know to those of skill or discovered after the filing of this application.

One skilled in the art is aware of a variety of therapeutic proteins or polypeptides, and the nucleic acids encoding them that will be beneficial for the treatment of angiogenesis-dependent diseases, including cancer therapy. In specific embodiments, such therapeutic proteins or polypeptides may can include, but not be limited to, suicide proteins, toxin proteins, pro-apoptotic proteins, cytokine proteins, and/or anti-angiogenic proteins.

In specific methods and compositions of the present invention, the therapeutic polypeptide or protein is a “suicide protein” that causes cell death by itself or in the presence of other compounds. A representative example of such a suicide protein is thymidine kinase of the herpes simplex virus. Additional examples include thymidine kinase of varicella zoster virus, the bacterial gene cytosine deaminase (which converts 5-fluorocytosine to the highly toxic compound 5-fluorouracil), p450 oxidoreductase, carboxypeptidase G2, β-glucuronidase, penicillin-V-amidase, penicillin-G-amidase, β-lactamase, nitroreductase, carboxypeptidase A, linamarase (also referred to as β-glucosidase), the E. coli gpt gene, and the E. coli Deo gene, although others are known in the art. In some embodiments, the suicide protein converts a prodrug into a toxic compound. As used herein, “prodrug” means any compound useful in the methods of the present invention that can be converted to a toxic product, i.e. toxic to tumor cells. The prodrug is converted to a toxic product by the suicide protein. Representative examples of such prodrugs include: ganciclovir, acyclovir, and FIAU (1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)-5-iodouracil) for thymidine kinase; ifosfamide for oxidoreductase; 6-methoxypurine arabinoside for VZV-TK; 5-fluorocytosine for cytosine deaminase; doxorubicin for β-glucuronidase; CB1954 and nitrofurazone for nitroreductase; and N-(Cyanoacetyl)-L-phenylalanine or N-(3-chloropropionyl)-L-phenylalanine for carboxypeptidase A. The prodrug may be administered readily by a person having ordinary skill in this art. A person with ordinary skill would readily be able to determine the most appropriate dose and route for the administration of the prodrug. In specific embodiments, the prodrug is administered in a dose of from about 1-20 mg/day/kg body weight, from about 1-50 mg/day/kg body weight, or about 1-100 mg/day/kg body weight.

In some embodiments, a therapeutic protein or polypeptide, is a cancer suppressor, for example p53 or Rb, or a nucleic acid encoding such a protein or polypeptide. Of course, those of skill know of a wide variety of such cancer suppressors and how to obtain them and/or the nucleic acids encoding them.

Other examples of therapeutic proteins or polypeptides include pro-apoptotic therapeutic proteins and polypeptides, for example, p15, p16, or p21^(WAF-1). One specific embodiment, involves pro-apototic proteins or polypeptides which are wild-type Bik or mutant Bik comprising similar or greater activity compared to wild-type Bik. In some specific embodiments further specific embodiment, the Bik mutant comprises a substitution at Thr³³, Ser³⁵, or both Thr³³and Ser³⁵. In an additional specific embodiment, the substitution is with Asp. U.S. Provisional Patent Application No. 60/459,901, filed Apr. 2, 2003, which is incorporated by reference herein in its entirety, describes Bik, mutant Biks, and nucleic acid sequences encoding them.

Cytokines, and nucleic acid encoding them may also be used as therapeutic proteins and polypeptided. Examples include: GM-CSF (granulocyte macrophage colony stimulating factor); TNFα (Tumor necrosis factor α); Interferons including, but not limited to, IFN α and IFN γ; and Interleukins including, but not limited to, Interleukin-1 (IL1), Interleukin-Beta (IL-beta), Interleukin-2 (IL2), Interleukin-4 (IL4), Interleukin-5 (IL5), Interleukin-6 (IL6), Interleukin-8 (IL8), Interleukin-10 (IL10), Interleukin-12 (IL12), Interleukin-13 (IL13), Interleukin-14 (IL14), Interleukin-15 (IL15), Interleukin-16 (IL16), Interleukin-18 (IL18), Interleukin-23 (IL23), Interleukin-24 (IL24), although other embodiments are known in the art.

An exemplary, but not limiting or comprehensive list of therapeutic proteins or polypeptides includes (followed in some cases by the a GenBank Accession No. for a nucleic acid encoding them): Herpes simplex virus type 1 (mutant KG111) thymidine kinase (SEQ ID NO:1; J04327); Herpes simplex virus type 2 (strain 9637) thymidine kinase (tk) (SEQ ID NO:2; M29941); Varicella zoster thymidine kinase (SEQ ID NO:3; M36160); Escherichia coli cytosine deaminase (SEQ ID NO:4; S56903); p450 oxidoreductase (SEQ ID NO:5; D17571); carboxypeptidase G2 (SEQ ID NO:6; M12599); β-glucuronidase (SEQ ID NO:7; M15182); penicillin-V-amidase (SEQ ID NO:8; M15660); penicillin-G-amidase (SEQ ID NO:9; AF161313); β-lactamase (SEQ ID NO:10; AY029068); nitroreductase (SEQ ID NO:11; A23284); carboxypeptidase A (SEQ ID NO:12; M27717); linamarase (SEQ ID NO:13; S35175); E.coli gpt (SEQ ID NO:14; X00221); E. coli Deo (SEQ ID NO:15; X03224); p53 (SEQ ID NO:16; AF307851); Rb (SEQ ID NO:17; XM_(—)053409); p15 (SEQ ID NO:18; U19796); p16 [(SEQ ID NO:19; U12818) (SEQ ID NO:20; U12819) and (SEQ ID NO:21; U12820)]; p21^(WAF-1) (SEQ ID NO:22; AF497972); GM-CSF (SEQ ID NO:23; M10663); TNF α (SEQ ID NO:24; AY066019); IFN α (SEQ ID NO:25; M34913); IFN α (SEQ ID NO:26; J00219); Interferon gamma; Interferon beta; IL1 (SEQ ID NO:27; M28983); IL-beta; IL2 (SEQ ID NO:28; K02056); IL3 (SEQ ID NO:29; M14743); IL4 (SEQ ID NO:30; M23442); IL5; IL6 (SEQ ID NO:31; M29150); IL7 (SEQ ID NO:32; J04156); IL8; IL10 (SEQ ID NO:33; U16720); IL12A (SEQ ID NO:34; NM_(—)000882); IL12B (SEQ ID NO:35; NM_(—)002187); IL13; IL14; IL15 (SEQ ID NO:36; U14407); IL16; IL18; IL23; IL24; Tumor Necrosis Factor SuperFamily member 14; Tumor Necrosis Factor SuperFamily member 13B (also called BlyS, BAFF, THANK); soluble form; Tumor Necrosis Factor Alpha; Tumor Necrosis Factor SuperFamily member 12 (also called Apo3L); Intercellular Adhesion Molecule-1; Lymphocyte Function-Associated antigen-3; Co-Stimulatory Molecule B7-1; Co-Stimulatory Molecule B7-2; FMS-related tyrosine kinase 3 ligand; CD40 Ligand; Surface antigen CD70; T-cell activation cell surface glycoprotein ligand; Co-Stimulatory Molecule OX-40 ligand (formerly gp34); TNF-related activation-induced cytokine; full-length (isoform 1, ODF; RANKL). Tumor Necrosis Factor SuperFamily member 11; TNF-related activation-induced cytokine; soluble form (isoform 2, sODF, sRANKL). Tumor Necrosis Factor SuperFamily member 11; Granulysin (NKG5); Granzyme A; Granzyme B; and Perforin.

Examples of diagnostic proteins include Green fluorescent protein (M62653; SEQ ID NO:41), Luciferase (SEQ ID NO:42), or a combination thereof.

In specific embodiments of the present invention, a nucleic acid segment encoding a therapeutic or diagnostic protein or polypeptide is comprised in a vector, such as a nonviral vector, a viral vector, or a combination thereof. The viral vector may be an adenoviral vector, a retroviral vector, or an adeno-associated viral vector. The nonviral vector may be a plasmid or a liposome. The nucleic acid segment may also be comprised in a pharmaceutical composition.

Any combinations of the therapeutic or diagnostic fusion nucleic acids could be delivered as gene therapy reagents to use against cancer or angiogenesis-dependent diseases as one component along with an antiangiogenic gene product listed herein or known in the art. Alternatively, fusion proteins encoded by these fusion genes could be expressed and purified for protein therapy targeting cancer and other angiogenesis dependent diseases.

A skilled artisan recognizes that a therapeutic sequence may also serve as a diagnostic sequence, and vice versa. In other embodiments, an angiogenesis inhibitor coupled to a diagnostic agent is used prior to angiogenesis inhibitor coupled to a therapeutic agent.

General Embodiments

The present invention regards targeting anti-angiogenic fusion polypeptides and/or the nucleic acids that encode them, as well as methods regarding the use of same. Thus, in exemplary embodiments, the present inventors demonstrate that endogenous angiogenesis inhibitors, such as endostatin, tumstatin, angiostatin, etc., could specifically target new blood vessel formation, which is a hallmark of angiogenesis-dependent diseases, including cancer. Although any cancer may be treated or prevented in accordance with the present invention, some examples include head and neck, ovarian, thyroid, oral, prostate, melanoma, colon cancer, breast cancer, angioma, sarcoma, lung cancer, brain cancer, pancreatic cancer, liver cancer, bladder cancer, gastrointestinal cancer, leukemia, lymphoma, and myeloma.

Specifically, these antiangiogenic proteins could be fused with therapeutic or diagnostic proteins and serve as a guiding tool to deliver the fusion protein to the vicinity of pathological angiogenic sites. These fusion proteins encoded by fusion gene constructs enhanced the therapeutic effects by combining functions of both antiangiogenic and therapeutic proteins. In addition, the targeting property contributed by antiangiogenic proteins could minimize the systemic toxic effect of therapeutic proteins by targeting the fusion proteins to the disease site(s).

In a specific embodiment, the present invention regards anti-angiogenic targeting fusion proteins to treat cancer in a mammal. For example, human ovarian cancer, pancreatic cancer, breast cancer, prostate cancer, and other cancers may be treated with compositions described herein or taught to a skilled artisan by analogous procedures described herein. In some embodiments, it is delivered by, for example, either a viral or non-viral delivery system into an appropriate recipient animal to inhibit angiogenesis, suppress tumor growth and development, or a combination thereof.

Exemplary anti-angiogenic targeting fusion proteins were generated. These fusions in preferred embodiments of the present invention, selectively inhibit angiogenesis, inhibit cell proliferation, inhibit cancer cell growth, or a combination thereof. One skilled in the art following the teachings of this specification can generate other exemplary anti-angiogenic targeting fusion proteins.

In some embodiments of the present invention, there are methods of preventing growth of a cell in an individual comprising administering to the individual an anti-angiogenic targeting fusion polypeptide. In specific embodiments, the polypeptide is administered in a liposome and/or the polypeptide further comprises a protein transduction domain (Schwarze et al., 1999). In some embodiments, an anti-angiogenic targeting fusion protein is administered as a polynucleotide, wherein the polynucleotide comprises an alteration that effects modification at the amino acid level, such as may be generated by site-directed mutagenesis. The modified anti-angiogenesis targeting fusion polynucleotide may be administered in a vector such as a plasmid, retroviral vector, adenoviral vector, adeno-associated viral vector, liposome, or a combination thereof.

There are also embodiments of the present invention wherein there are methods of treating a cell comprising contacting the cell with an anti-angiogenic targeting fusion polypeptide. In specific embodiments, the cell is a human cell, the cell is comprised in an animal, and/or the animal is human.

Targeting Fusion Production

While the chimeric proteins of the present invention may be produced by chemical synthetic methods or by chemical linkage between the two moieties, it is preferred that they are produced by fusion of a coding sequence of an antiangiogenic moiety and a coding sequence of a therapeutic or diagnostic moiety under the control of a regulatory sequence that directs the expression of the fusion polynucleotide in an appropriate host cell. In preferred embodiments, each of the components of the chimeric protein comprise functional activity for their respective parts being an antiangiogenic moiety and a therapeutic or diagnostic moiety.

The fusion of two full-length coding sequences can be achieved by methods well known in the art of molecular biology. It is preferred that a fusion polynucleotide contain only the AUG translation initiation codon at the 5′ end of the first coding sequence without the initiation codon of the second coding sequence to avoid the production of two separate encoded products. In addition, a leader sequence may be placed at the 5′ end of the polynucleotide in order to target the expressed product to a specific site or compartment within a host cell to facilitate secretion or subsequent purification after gene expression. The two coding sequences can be fused directly without any linker or by using a linker. In a specific embodiment, a linker for connecting the antiangiogenic and therapeutic/diagnostic proteins comprises either VPGVG (elastin Val-Pro-Gly-Val-Gly) or Gly-Gly-Gly-Ser-Gly. Other linkers are known to those of skill in the art, such as are described in WO 99/16889, which is incorporated by reference herein in its entirety.

In accordance with the objects of the present invention, a polynucleotide that encodes a fusion protein may be used to generate recombinant DNA molecules that direct the expression of the fusion protein, fusion peptide fragments, or a functional equivalent thereof, in appropriate cells. Due to the inherent degeneracy of the genetic code, other DNA sequences that encode substantially the same or a functionally equivalent amino acid sequence, may be used in the practice of the invention of the cloning and expression of the fusion protein. Such DNA sequences include those capable of hybridizing to the fusion sequences or their complementary sequences under stringent conditions, which are well known to a skilled artisan.

Altered DNA sequences that may be used in accordance with the invention include deletions, additions or substitutions of different nucleotide residues resulting in a sequence that encodes the same or a functionally equivalent fusion gene product. The gene product itself may contain deletions, additions or substitutions of amino acid residues within a fusion sequence, which result in a silent change thus producing a functionally equivalent fusion protein. Such amino acid substitutions may be made on the basis of similarity in polarity, charge, solubility, hydrophobicity, hydrophilicity, and/or the amphipathic nature of the residues involved, which is well known to a skilled artisan.

The DNA sequences of the invention may be engineered in order to alter a fusion coding sequence for a variety of ends, including but not limited to, alterations that modify processing and expression of the gene product, as described elsewhere in greater detail. For example, mutations may be introduced using techniques which are well known in the art, e.g., site-directed mutagenesis, to insert new restriction sites, to alter glycosylation patterns, phosphorylation, etc.

In one embodiment of the invention, the coding sequence of the fusion protein could be synthesized in whole or in part, using chemical methods well known in the art. (See, for example, Caruthers et al., 1980; Crea and Horn, 1980; and Chow and Kempe, 1981). For example, active domains of the moieties can be synthesized by solid phase techniques, cleaved from the resin, and purified by preparative high performance liquid chromatography followed by chemical linkage to form a chimeric protein. (e.g., see Creighton, 1983, Proteins Structures And Molecular Principles, W. H. Freeman and Co., N.Y. pp. 50-60). The composition of the synthetic peptides may be confirmed by amino acid analysis or sequencing (e.g., the Edman degradation procedure; see Creighton, 1983, Proteins, Structures and Molecular Principles, W. H. Freeman and Co., N.Y. pp. 34-49). Alternatively, the two moieties of the fusion protein produced by synthetic or recombinant methods may be conjugated by chemical linkers according to methods well known in the art (Brinkmann and Pastan, 1994).

In order to express a biologically active fusion protein, the nucleotide sequence coding for a chimeric protein, or a functional equivalent, is inserted into an appropriate expression vector, i.e., a vector which contains the necessary elements for the transcription and translation of the inserted coding sequence, as described elsewherein in greater detail. The fusion gene products as well as host cells or cell lines transfected or transformed with recombinant fusion expression vectors can be used for a variety of purposes. These include but are not limited to generating antibodies (i.e., monoclonal or polyclonal) that bind to epitopes of the proteins to facilitate their purification.

Methods that are well known to those skilled in the art can be used to construct expression vectors containing the fusion protein coding sequence and appropriate transcriptional/translational control signals, as discussed elsewhere in greater detail. These methods include in vitro recombinant DNA techniques, synthetic techniques and in vivo recombination/genetic recombination.

A variety of host-expression vector systems may be utilized to express the fusion protein coding sequence, and these are well known in the art.

Specific initiation signals may be required for efficient translation of the inserted fusion protein coding sequence. These signals include the ATG initiation codon and adjacent sequences. In cases where the entire fusion gene, including its own initiation codon and adjacent sequences, is inserted into the appropriate expression vector, no additional translational control signals may be needed. However, in cases where the fusion protein coding sequence does not include its own initiation codon, exogenous translational control signals, including the ATG initiation codon, must be provided. Furthermore, the initiation codon must be in phase with the reading frame of the fusion protein coding sequence to ensure translation of the entire insert. These exogenous translational control signals and initiation codons can be of a variety of origins, both natural and synthetic. The efficiency of expression may be enhanced by the inclusion of appropriate transcription enhancer elements, transcription terminators, etc. (see Bittner et al., 1987).

Definitions and Techniques Affecting Targeting Fusion Gene Products and Genes

Targeting Fusion Gene Products and Genes

As used herein, the terms “targeting fusion gene product” and “targeting fusion” refer to proteins or polypeptides having amino acid sequences that comprise at least one anti-angiogenesis component and at least one therapeutic and/or diagnostic component in said fusion and that are biologically active in that they are capable performing similar activities to at least one of their native components, and in some embodiments both components are capable of performing activities similar to the native separate components. For example, they are preferably capable of anti-angiogenesis activity, pro-apoptotic activity, anti-cell proliferative activity, anti-tumor activity and/or cross-reactive antibody activity with an anti-targeting fusion antibody raised against at least one component of the targeting fusion gene product. The term “targeting fusion gene product” includes analogs of targeting fusion molecules that exhibit at least some biological activity in common with native targeting fusion. Furthermore, those skilled in the art of mutagenesis will appreciate that other analogs, as yet undisclosed or undiscovered, may be used to construct targeting fusion analogs.

The term “mutant form of targeting fusion” refers to any DNA sequence that is substantially identical to a DNA sequence encoding at least a part of the targeting fusion gene product as defined above. The term also refers to RNA or antisense sequences compatible with such DNA sequences. A “targeting fusion gene” may also comprise any combination of associated control sequences.

The term “substantially identical”, when used to define either a targeting fusion amino acid sequence or targeting fusion nucleic acid sequence, means that a particular subject sequence, for example, a mutant sequence, varies from the sequence of its separate components by, for example, one or more substitutions, deletions, additions, or a combination thereof, the net effect of which is to retain at least some biological activity of at least part of the respective component part. Alternatively, DNA analog sequences are “substantially identical” to specific DNA sequences disclosed herein if: (a) the DNA analog sequence is derived from at least part of a coding region of the targeting fusion gene; or (b) the DNA analog sequence is capable at least in part of hybridization of DNA sequences of (a) under moderately stringent conditions and which encode biologically active targeting fusion; or (c) DNA sequences that are degenerative as a result of the genetic code at least part of to the DNA analog sequences defined in (a) or (b). Substantially identical analog proteins will be greater than about 80% similar to the corresponding sequence of the native protein component. Sequences having lesser degrees of similarity but comparable biological activity are considered to be equivalents. In determining nucleic acid sequences, all subject nucleic acid sequences capable of encoding substantially similar amino acid sequences are considered to be substantially similar to a reference nucleic acid sequence, regardless of differences in codon sequence.

Percent Similarity

Percent similarity may be determined, for example, by comparing sequence information using the GAP computer program, available from the University of Wisconsin Geneticist Computer Group. The GAP program utilizes the alignment method of Needleman et al., 1970, as revised by Smith et al., 1981. Briefly, the GAP program defines similarity as the number of aligned symbols (i.e. nucleotides or amino acids) which are similar, divided by the total number of symbols in the shorter of the two sequences. The preferred default parameters for the GAP program include (1) a unitary comparison matrix (containing a value of 1 for identities and 0 for non-identities) of nucleotides and the weighted comparison matrix of Gribskov et al., 1986, as described by Schwartz et al., 1979; (2) a penalty of 3.0 for each gap and an additional 0.01 penalty for each symbol and each gap; and (3) no penalty for end gaps.

Nucleic Acid Sequences

In certain embodiments, the invention concerns the use of targeting fusion nucleic acids, genes and gene products, or the corresponding protein, polypeptide, or peptide. The term “a sequence essentially as targeting fusion” means that the sequence substantially corresponds to at least a portion of the targeting fusion gene and has relatively few bases or amino acids (whether DNA or protein) that are not identical to those of targeting fusion (or a biologically functional equivalent thereof, when referring to proteins). The term “biologically functional equivalent” is well understood in the art and is further defined in detail herein. Accordingly, sequences that have between about 70% and about 80%; or more preferably, between about 81% and about 90%; or even more preferably, between about 91% and about 99%; of amino acids that are identical or functionally equivalent to at least part of the amino acids of targeting fusion will be sequences that are “essentially the same”.

Targeting fusion nucleic acids that have at least part of their sequence comprising functionally equivalent codons are covered by the invention. The term “functionally equivalent codon” is used herein to refer to codons that encode the same amino acid, such as the six codons for arginine or serine, and also refers to codons that encode biologically equivalent amino acids (Table 1).

Amino Acids Codons Alanine Ala A GCA GCC GCG GCU Cysteine Cys C UGC UGU Aspartic Acid Asp D GAC GAU Glutamic Acid Glu E GAA GAG Phenylalanine Phe F UUC UUU Glycine Gly G GGA GGC GGG GGU Histidine His H CAC CAU Isoleucine Ile I AUA AUC AUU Lysine Lys K AAA AAG Leucine Leu L UUA UUG CUA CUC CUG CUU Methionine Met M AUG Asparagine Asn N AAC AAU Proline Pro P CCA CCC CCU Glutamine Gln Q CAA CAG Arginine Arg R AGA AGG CGA CGC CGG CGU Serine Ser S AGC AGU UCA UCC UCG UCU Threonine Thr T ACA ACC ACG ACU Valine Val V GUA GUC GUG GUU Tryptophan Trp W UGG Tyrosine Tyr Y UAC UAU

It will also be understood that amino acid and nucleic acid sequences may include additional residues, such as additional N- or C-terminal amino acids or 5′ or 3′ sequences, and yet still be essentially as set forth in one of the sequences disclosed herein, so long as the sequence meets the criteria set forth above, including the maintenance of biological protein activity where protein expression is concerned. The addition of terminal sequences particularly applies to nucleic acid sequences which may, for example, include various non-coding sequences flanking either of the 5′ or 3′ portions of the coding region or may include various internal sequences, i.e., introns, which are known to occur within genes.

The present invention also encompasses the use of DNA segments that are complementary, or essentially complementary, to the sequences set forth in the specification. Nucleic acid sequences that are “complementary” are those that are capable of base-pairing according to the standard Watson-Crick complementarity rules. As used herein, the term “complementary sequences” means nucleic acid sequences that are substantially complementary, as may be assessed by the same nucleotide comparison set forth above, or as defined as being capable of hybridizing to the nucleic acid segment in question under relatively stringent conditions such as those described herein.

Biologically Functional Equivalents

As mentioned above, modification and changes may be made in at least part of the structure of angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, such as an antiangiogenesis targeting fusion, and still obtain a molecule having like or otherwise desirable characteristics. In a specific embodiment, a skilled artisan recognizes that the scope of the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent comprises an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region or a nucleic acid encoding a fusion protein comprising an antiangiogenesis polypeptide region linked to a therapeutic protein or polypeptide region or a diagnostic protein or polypeptide region.

For example, certain amino acids may be substituted for other amino acids in a protein structure without appreciable loss of activity. Since, in many embodiments, it is the interactive capacity and nature of a protein that defines that protein's biological functional activity, certain amino acid sequence substitutions can be made in a protein sequence (or, of course, its underlying DNA coding sequence) and nevertheless obtain a protein with like or even countervailing properties (e.g., antagonistic vs. agonistic). It is thus contemplated by the inventors that various changes may be made in at least part of the sequence of the targeting fusion proteins or peptides (or underlying DNA) without appreciable loss of their desired biological utility or activity.

It is also well understood by the skilled artisan that, inherent in the definition of a biologically functional equivalent protein or peptide, is the concept that there is a limit to the number of changes that may be made within a defined portion of the molecule and still result in a molecule with an acceptable level of equivalent biological activity. Biologically functional equivalent peptides are thus defined herein as those peptides in which certain, not most or all, of the amino acids may be substituted. Of course, a plurality of distinct proteins/peptides with different substitutions may easily be made and used in accordance with the invention.

It is also well understood that where certain residues are shown to be particularly important to the biological or structural properties of a protein or peptide, e.g., residues in active sites, such residues may not generally be exchanged.

Amino acid substitutions, such as those that might be employed in modifying targeting fusion, are generally based on the relative similarity of the amino acid side-chain substituents, for example, their hydrophobicity, hydrophilicity, charge, size, and the like. An analysis of the size, shape and type of the amino acid side-chain substituents reveals that arginine, lysine and histidine are all positively charged residues; that alanine, glycine and serine are all a similar size; and that phenylalanine, tryptophan and tyrosine all have a generally similar shape. Therefore, based upon these considerations, arginine, lysine and histidine; alanine, glycine and serine; and phenylalanine, tryptophan and tyrosine; are defined herein as biologically functional equivalents.

In making such changes, the hydropathic index of amino acids may be considered. Each amino acid has been assigned a hydropathic index on the basis of their hydrophobicity and charge characteristics, these are: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine (−1.3); proline (−1.6); histidine (−3.2); glutamate (−3.5); glutamine (−3.5); aspartate (−3.5); asparagine (−3.5); lysine (−3.9); and arginine (−4.5).

The importance of the hydropathic amino acid index in conferring interactive biological function on a protein is generally understood in the art (Kyte and Doolittle, 1982, incorporated herein by reference). It is known that certain amino acids may be substituted for other amino acids having a similar hydropathic index or score and still retain a similar biological activity. In making changes based upon the hydropathic index, the substitution of amino acids whose hydropathic indices are within ±2 is preferred, those that are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred.

It is also understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity. U.S. Pat. No. 4,554,101, incorporated herein by reference, states that the greatest local average hydrophilicity of a protein, as governed by the hydrophilicity of its adjacent amino acids, correlates with its immunogenicity and antigenicity, i.e. with a biological property of the protein. It is understood that an amino acid can be substituted for another having a similar hydrophilicity value and still obtain a biologically equivalent protein.

As detailed in U.S. Pat. No. 4,554,101, the following hydrophilicity values have been assigned to amino acid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0.+−0.1); glutamate (+3.0.+−0.1); serine (+0.3); asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (−0.4); proline (−0.5.+−0.1); alanine (−0.5); histidine (−0.5); cysteine (−1.0); methionine (−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8); tyrosine (−2.3); phenylalanine (−2.5); tryptophan (−3.4).

In making changes based upon similar hydrophilicity values, the substitution of amino acids whose hydrophilicity values are within ±2 is preferred, those that are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred.

While discussion has focused on functionally equivalent polypeptides arising from amino acid changes, it will be appreciated that these changes may be effected by alteration of the encoding DNA; taking into consideration also that the genetic code is degenerate and that two or more codons may code for the same amino acid.

Combination Treatments

In order to increase the effectiveness of an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, such as an anti-angiogenic targeting fusion protein, or expression construct coding therefore, it may be desirable to combine these compositions with other agents effective in the treatment of disease related to angiogenesis, such as, for example, anti-cancer agents for cancer. An “anti-cancer” agent is capable of negatively affecting cancer in a subject, for example, by inhibiting angiogenesis for a cancer cell and/or tissue, killing cancer cells, inducing apoptosis in cancer cells, reducing the growth rate of cancer cells, reducing the incidence or number of metastases, reducing tumor size, inhibiting tumor growth, reducing the blood supply to a tumor or cancer cells, promoting an immune response against cancer cells or a tumor, preventing or inhibiting the progression of cancer, or increasing the lifespan of a subject with cancer. More generally, these other compositions would be provided in a combined amount effective to kill or inhibit proliferation of the cell. This process may involve contacting the cells with the expression construct and the agent(s) or multiple factor(s) at the same time. This may be achieved by contacting the cell with a single composition or pharmacological formulation that includes both agents, or by contacting the cell with two distinct compositions or formulations, at the same time, wherein one composition includes the expression construct and the other includes the second agent(s).

Tumor cell resistance to chemotherapy and radiotherapy agents represents a major problem in clinical oncology. One goal of current cancer research is to find ways to improve the efficacy of chemo- and radiotherapy by combining it with gene therapy. For example, the herpes simplex-thymidine kinase (HS-tK) gene, when delivered to brain tumors by a retroviral vector system, successfully induced susceptibility to the antiviral agent ganciclovir (Culver et al., 1992). In the context of the present invention, it is contemplated that targeting fusion gene therapy could be used similarly in conjunction with chemotherapeutic, radiotherapeutic, or immunotherapeutic intervention, in addition to other pro-apoptotic or cell cycle regulating agents.

Alternatively, the combination therapy may precede or follow the other agent treatment by intervals ranging from minutes to weeks. In embodiments where the other agent and expression construct are applied separately to the cell, one would generally ensure that a significant period of time did not expire between the time of each delivery, such that the agent and expression construct would still be able to exert an advantageously combined effect on the cell. In such instances, it is contemplated that one may contact the cell with both modalities within about 12-24 h of each other and, more preferably, within about 6-12 h of each other. In some situations, it may be desirable to extend the time period for treatment significantly, however, where several d (2, 3, 4, 5, 6 or 7) to several wk (1, 2, 3, 4, 5, 6, 7 or 8) lapse between the respective administrations.

Various combinations, in an exemplary embodiment, may be employed, although gene therapy is “A” and the secondary agent, such as radiotherapy, chemotherapy, surgery, or immunotherapy is “B”:

A/B/A B/A/B B/B/A A/A/B A/B/B B/A/A A/B/B/B B/A/B/B B/B/B/A B/B/A/B A/A/B/B A/B/A/B A/B/B/A B/B/A/A B/A/B/A B/A/A/B A/A/A/B B/A/A/A A/B/A/A A/A/B/A

Administration of the therapeutic expression constructs of the present invention to a patient will follow general protocols for the administration of chemotherapeutics, taking into account the toxicity, if any, of the vector. It is expected that the treatment cycles would be repeated as necessary. It also is contemplated that various standard therapies, as well as surgical intervention, may be applied in combination with the described hyperproliferative cell therapy.

Nucleic Acid-Based Expression Systems

Vectors

In one embodiment, a targeting fusion nucleic acid is comprised on a vector. The term “vector” is used to refer to a carrier nucleic acid molecule into which a nucleic acid sequence can be inserted for introduction into a cell where it can be replicated. A nucleic acid sequence can be “exogenous,” which means that it is foreign to the cell into which the vector is being introduced or that the sequence is homologous to a sequence in the cell but in a position within the host cell nucleic acid in which the sequence is ordinarily not found. Vectors include plasmids, cosmids, viruses (bacteriophage, animal viruses, and plant viruses), and artificial chromosomes (e.g., YACs). One of skill in the art would be well equipped to construct a vector through standard recombinant techniques, which are described in Maniatis et al., 1988 and Ausubel et al., 1994, both incorporated herein by reference.

The term “expression vector” refers to a vector containing a nucleic acid sequence coding for at least part of a gene product capable of being transcribed. In some cases, RNA molecules are then translated into a protein, polypeptide, or peptide. In other cases, these sequences are not translated, for example, in the production of antisense molecules or ribozymes. Expression vectors can contain a variety of “control sequences,” which refer to nucleic acid sequences necessary for the transcription and possibly translation of an operably linked coding sequence in a particular host organism. In addition to control sequences that govern transcription and translation, vectors and expression vectors may contain nucleic acid sequences that serve other functions as well and are described infra.

Promoters and Enhancers

A “promoter” is a control sequence that is a region of a nucleic acid sequence at which initiation and rate of transcription are controlled. It may contain genetic elements at which regulatory proteins and molecules may bind such as RNA polymerase and other transcription factors. The phrases “operatively positioned,” “operatively linked,” “under control,” and “under transcriptional control” mean that a promoter is in a correct functional location and/or orientation in relation to a nucleic acid sequence to control transcriptional initiation and/or expression of that sequence. A promoter may or may not be used in conjunction with an “enhancer,” which refers to a cis-acting regulatory sequence involved in the transcriptional activation of a nucleic acid sequence.

A promoter may be one naturally associated with a gene or sequence, as may be obtained by isolating the 5′ non-coding sequences located upstream of the coding segment and/or exon. Such a promoter can be referred to as “endogenous.” Similarly, an enhancer may be one naturally associated with a nucleic acid sequence, located either downstream or upstream of that sequence. Alternatively, certain advantages will be gained by positioning the coding nucleic acid segment under the control of a recombinant or heterologous promoter, which refers to a promoter that is not normally associated with a nucleic acid sequence in its natural environment. A recombinant or heterologous enhancer refers also to an enhancer not normally associated with a nucleic acid sequence in its natural environment. Such promoters or enhancers may include promoters or enhancers of other genes, and promoters or enhancers isolated from any other prokaryotic, viral, or eukaryotic cell, and promoters or enhancers not “naturally occurring,” i.e., containing different elements of different transcriptional regulatory regions, and/or mutations that alter expression. In addition to producing nucleic acid sequences of promoters and enhancers synthetically, sequences may be produced using recombinant cloning and/or nucleic acid amplification technology, including PCR™, in connection with the compositions disclosed herein (see U.S. Pat. No. 4,683,202; U.S. Pat. No. 5,928,906, each incorporated herein by reference). Furthermore, it is contemplated the control sequences that direct transcription and/or expression of sequences within non-nuclear organelles such as mitochondria, chloroplasts, and the like, can be employed as well.

Naturally, it will be important to employ a promoter and/or enhancer that effectively directs the expression of the DNA segment in the cell type, organelle, and organism chosen for expression. Those of skill in the art of molecular biology generally know the use of promoters, enhancers, and cell type combinations for protein expression, for example, see Sambrook et al. (1989), incorporated herein by reference. The promoters employed may be constitutive, tissue-specific, inducible, and/or useful under the appropriate conditions to direct high level expression of the introduced DNA segment, such as is advantageous in the large-scale production of recombinant proteins and/or peptides. The promoter may be heterologous or endogenous.

In a specific embodiment, a promoter is utilized that is tissue-specific and/or specific to the microenvironment surrounding the diseased tissue (such as the tumor), cell-specific, or cell type-specific. In a specific embodiment, a promoter such as one described in U.S. Provisional Patent Application Ser. No. 60/377,672, filed May 5, 2002, and entitled “BIPARTITE T-CELL FACTOR (TCF)-RESPONSIVE PROMOTER” and in U.S. Nonprovisional Patent Application Ser. No. 10/429,802, filed May 5, 2003 under Express Mail number EU 110397859US, both of which are incorporated by reference herein in their entirety, is utilized in the present invention.

The identity of tissue-specific promoters or elements, as well as assays to characterize their activity, is well known to those of skill in the art. Examples of such regions include the human LIMK2 gene (Nomoto et al. 1999), the somatostatin receptor 2 gene (Kraus et al., 1998), murine epididymal retinoic acid-binding gene (Lareyre et al., 1999), human CD4 (Zhao-Emonet et al., 1998), mouse alpha2 (XI) collagen (Tsumaki, et al., 1998), D1A dopamine receptor gene (Lee, et al., 1997), insulin-like growth factor II (Wu et al., 1997), human platelet endothelial cell adhesion molecule-1 (Almendro et al., 1996).

Initiation Signals and Internal Ribosome Binding Sites

A specific initiation signal also may be required for efficient translation of coding sequences. These signals include the ATG initiation codon or adjacent sequences. Exogenous translational control signals, including the ATG initiation codon, may need to be provided. One of ordinary skill in the art would readily be capable of determining this and providing the necessary signals. It is well known that the initiation codon must be “in-frame” with the reading frame of the desired coding sequence to ensure translation of the entire insert. The exogenous translational control signals and initiation codons can be either natural or synthetic. The efficiency of expression may be enhanced by the inclusion of appropriate transcription enhancer elements.

In certain embodiments of the invention, the use of internal ribosome entry sites (IRES) elements are used to create multigene, or polycistronic, messages. IRES elements are able to bypass the ribosome scanning model of 5′ methylated Cap dependent translation and begin translation at internal sites (Pelletier and Sonenberg, 1988). IRES elements from two members of the picornavirus family (polio and encephalomyocarditis) have been described (Pelletier and Sonenberg, 1988), as well an IRES from a mammalian message (Macejak and Sarnow, 1991). IRES elements can be linked to heterologous open reading frames. Multiple open reading frames can be transcribed together, each separated by an IRES, creating polycistronic messages. By virtue of the IRES element, each open reading frame is accessible to ribosomes for efficient translation. Multiple genes can be efficiently expressed using a single promoter/enhancer to transcribe a single message (see U.S. Pat. Nos. 5,925,565 and 5,935,819, herein incorporated by reference).

Multiple Cloning Sites

Vectors can include a multiple cloning site (MCS), which is a nucleic acid region that contains multiple restriction enzyme sites, any of which can be used in conjunction with standard recombinant technology to digest the vector. (See Carbonelli et al., 1999, Levenson et al., 1998, and Cocea, 1997, incorporated herein by reference.) “Restriction enzyme digestion” refers to catalytic cleavage of a nucleic acid molecule with an enzyme that functions only at specific locations in a nucleic acid molecule. Many of these restriction enzymes are commercially available. Use of such enzymes is widely understood by those of skill in the art. Frequently, a vector is linearized or fragmented using a restriction enzyme that cuts within the MCS to enable exogenous sequences to be ligated to the vector. “Ligation” refers to the process of forming phosphodiester bonds between two nucleic acid fragments, which may or may not be contiguous with each other. Techniques involving restriction enzymes and ligation reactions are well known to those of skill in the art of recombinant technology.

Splicing Sites

Most transcribed eukaryotic RNA molecules will undergo RNA splicing to remove introns from the primary transcripts. Vectors containing genomic eukaryotic sequences may require donor and/or acceptor splicing sites to ensure proper processing of the transcript for protein expression. (See Chandler et al., 1997, herein incorporated by reference.)

Polyadenylation Signals

In expression, one will typically include a polyadenylation signal to effect proper polyadenylation of the transcript. The nature of the polyadenylation signal is not believed to be crucial to the successful practice of the invention, and/or any such sequence may be employed. Preferred embodiments include the SV40 polyadenylation signal and/or the bovine growth hormone polyadenylation signal, convenient and/or known to function well in various target cells. Also contemplated as an element of the expression cassette is a transcriptional termination site. These elements can serve to enhance message levels and/or to minimize read through from the cassette into other sequences.

Origins of Replication

In order to propagate a vector in a host cell, it may contain one or more origins of replication sites (often termed “ori”), which is a specific nucleic acid sequence at which replication is initiated. Alternatively an autonomously replicating sequence (ARS) can be employed if the host cell is yeast.

Selectable and Screenable Markers

In certain embodiments of the invention, the cells contain nucleic acid construct of the present invention, a cell may be identified in vitro or in vivo by including a marker in the expression vector. Such markers would confer an identifiable change to the cell permitting easy identification of cells containing the expression vector. Generally, a selectable marker is one that confers a property that allows for selection. A positive selectable marker is one in which the presence of the marker allows for its selection, while a negative selectable marker is one in which its presence prevents its selection. An example of a positive selectable marker is a drug resistance marker.

Usually the inclusion of a drug selection marker aids in the cloning and identification of transformants, for example, genes that confer resistance to neomycin, puromycin, hygromycin, DHFR, GPT, zeocin and histidinol are useful selectable markers. In addition to markers conferring a phenotype that allows for the discrimination of transformants based on the implementation of conditions, other types of markers including screenable markers such as GFP, whose basis is calorimetric analysis, are also contemplated. Alternatively, screenable enzymes such as herpes simplex virus thymidine kinase (tk) or chloramphenicol acetyltransferase (CAT) may be utilized. One of skill in the art would also know how to employ immunologic markers, possibly in conjunction with FACS analysis. The marker used is not believed to be important, so long as it is capable of being expressed simultaneously with the nucleic acid encoding a gene product. Further examples of selectable and screenable markers are well known to one of skill in the art.

Host Cells

As used herein, the terms “cell,” “cell line,” and “cell culture” may be used interchangeably. All of these term also include their progeny, which is any and all subsequent generations. It is understood that all progeny may not be identical due to deliberate or inadvertent mutations. In the context of expressing a heterologous nucleic acid sequence, “host cell” refers to a prokaryotic or eukaryotic cell, and it includes any transformable organisms that is capable of replicating a vector and/or expressing a heterologous gene encoded by a vector. A host cell can, and has been, used as a recipient for vectors. A host cell may be “transfected” or “transformed,” which refers to a process by which exogenous nucleic acid is transferred or introduced into the host cell. A transformed cell includes the primary subject cell and its progeny.

Host cells may be derived from prokaryotes or eukaryotes, depending upon whether the desired result is replication of the vector or expression of part or all of the vector-encoded nucleic acid sequences. Numerous cell lines and cultures are available for use as a host cell, and they can be obtained through the American Type Culture Collection (ATCC), which is an organization that serves as an archive for living cultures and genetic materials (www.atcc.org). An appropriate host can be determined by one of skill in the art based on the vector backbone and the desired result. A plasmid or cosmid, for example, can be introduced into a prokaryote host cell for replication of many vectors. Bacterial cells used as host cells for vector replication and/or expression include DH5α, JM109, and KC8, as well as a number of commercially available bacterial hosts such as SURE® Competent Cells and SOLOPACK™ Gold Cells (STRATAGENE®, La Jolla). Alternatively, bacterial cells such as E. coli LE392 could be used as host cells for phage viruses.

Examples of eukaryotic host cells for replication and/or expression of a vector include HeLa, NIH3T3, Jurkat, 293, Cos, CHO, Saos, and PC12. Many host cells from various cell types and organisms are available and would be known to one of skill in the art. Similarly, a viral vector may be used in conjunction with either a eukaryotic or prokaryotic host cell, particularly one that is permissive for replication or expression of the vector.

Some vectors may employ control sequences that allow it to be replicated and/or expressed in both prokaryotic and eukaryotic cells. One of skill in the art would further understand the conditions under which to incubate all of the above described host cells to maintain them and to permit replication of a vector. Also understood and known are techniques and conditions that would allow large-scale production of vectors, as well as production of the nucleic acids encoded by vectors and their cognate polypeptides, proteins, or peptides.

Expression Systems

Numerous expression systems exist that comprise at least a part or all of the compositions discussed above. Prokaryote- and/or eukaryote-based systems can be employed for use with the present invention to produce nucleic acid sequences, or their cognate polypeptides, proteins and peptides. Many such systems are commercially and widely available.

The insect cell/baculovirus system can produce a high level of protein expression of a heterologous nucleic acid segment, such as described in U.S. Pat. Nos. 5,871,986, 4,879,236, both herein incorporated by reference, and which can be bought, for example, under the name MAXBAC® 2.0 from INVITROGEN® and BACPACK™ BACULOVIRUS EXPRESSION SYSTEM FROM CLONTECH®.

Other examples of expression systems include STRATAGENE®'s COMPLETE CONTROL™ Inducible Mammalian Expression System, which involves a synthetic ecdysone-inducible receptor, or its pET Expression System, an E. coli expression system. Another example of an inducible expression system is available from INVITROGEN®, which carries the T-REX™ (tetracycline-regulated expression) System, an inducible mammalian expression system that uses the full-length CMV promoter. INVITROGEN® also provides a yeast expression system called the Pichia methanolica Expression System, which is designed for high-level production of recombinant proteins in the methylotrophic yeast Pichia methanolica. One of skill in the art would know how to express a vector, such as an expression construct, to produce a nucleic acid sequence or its cognate polypeptide, protein, or peptide.

Nucleic Acid Delivery

The general approach to the aspects of the present invention concerning compositions and/or therapeutics is to provide a cell with a gene construct encoding a specific and/or desired protein, polypeptide and peptide, thereby permitting the desired activity of the proteins to take effect. In the present invention, the desired protein, polypeptide, or peptide is a targeting fusion comprising an angiogenesis inhibitor and a therapeutic or diagnostic sequence. While it is conceivable that the gene construct and/or protein may be delivered directly, a preferred embodiment involves providing a nucleic acid encoding a specific and desired protein, polypeptide and peptide to the cell. Following this provision, the proteinaceous composition is synthesized by the transcriptional and translational machinery of the cell, as well as any that may be provided by the expression construct. In providing antisense, ribozymes and other inhibitors, the preferred mode is also to provide a nucleic acid encoding the construct to the cell.

In certain embodiments of the invention, the nucleic acid encoding the gene may be stably integrated into the genome of the cell. In yet further embodiments, the nucleic acid may be stably maintained in the cell as a separate, episomal segment of DNA. Such nucleic acid segments and “episomes” encode sequences sufficient to permit maintenance and replication independent of and in synchronization with the host cell cycle. How the expression construct is delivered to a cell and/or where in the cell the nucleic acid remains is dependent on the type of expression construct employed.

DNA Delivery Using Viral Vectors

The ability of certain viruses to infect cells and enter cells via receptor-mediated endocytosis, and to integrate into host cell genome and/or express viral genes stably and/or efficiently have made them attractive candidates for the transfer of foreign genes into mammalian cells. Preferred gene therapy vectors of the present invention will generally be viral vectors.

Although some viruses that can accept foreign genetic material are limited in the number of nucleotides they can accommodate and/or in the range of cells they infect, these viruses have been demonstrated to successfully effect gene expression. However, adenoviruses do not integrate their genetic material into the host genome and/or therefore do not require host replication for gene expression, making them ideally suited for rapid, efficient, heterologous gene expression. Techniques for preparing replication-defective infective viruses are well known in the art.

Of course, in using viral delivery systems, one will desire to purify the virion sufficiently to render it essentially free of undesirable contaminants, such as defective interfering viral particles and endotoxins and other pyrogens such that it will not cause any untoward reactions in the cell, animal and/or individual receiving the vector construct. A preferred means of purifying the vector involves the use of buoyant density gradients, such as cesium chloride gradient centrifugation

Adenoviral Vectors

A particular method for delivery of the expression constructs involves the use of an adenovirus expression vector. Although adenovirus vectors are known to have a low capacity for integration into genomic DNA, this feature is counterbalanced by the high efficiency of gene transfer afforded by these vectors. “Adenovirus expression vector” is meant to include those constructs containing adenovirus sequences sufficient to (a) support packaging of the construct and/or (b) to ultimately express a tissue and/or cell-specific construct that has been cloned therein.

The expression vector comprises a genetically engineered form of adenovirus. Knowledge of the genetic organization and adenovirus, a 36 kb, linear, double-stranded DNA virus, allows substitution of large pieces of adenoviral DNA with foreign sequences up to 7 kb (Grunhaus and Horwitz, 1992). In contrast to retrovirus, the adenoviral infection of host cells does not result in chromosomal integration because adenoviral DNA can replicate in an episomal manner without potential genotoxicity. Also, adenoviruses are structurally stable, and/or no genome rearrangement has been detected after extensive amplification.

Adenovirus is particularly suitable for use as a gene transfer vector because of its mid-sized genome, ease of manipulation, high titer, wide target-cell range and/or high infectivity. Both ends of the viral genome contain 100-200 base pair inverted repeats (ITRs), which are cis elements necessary for viral DNA replication and/or packaging. The early (E) and/or late (L) regions of the genome contain different transcription units that are divided by the onset of viral DNA replication. The E1 region (E1A and/or E1B) encodes proteins responsible for the regulation of transcription of the viral genome and/or a few cellular genes. The expression of the E2 region (E2A and/or E2B) results in the synthesis of the proteins for viral DNA replication. These proteins are involved in DNA replication, late gene expression and/or host cell shut-off (Renan, 1990). The products of the late genes, including the majority of the viral capsid proteins, are expressed only after significant processing of a single primary transcript issued by the major late promoter (MLP). The MLP (located at 16.8 m.u.) is particularly efficient during the late phase of infection, and/or all the mRNA's issued from this promoter possess a 5′-tripartite leader (TPL) sequence which makes them preferred mRNA's for translation.

In a current system, recombinant adenovirus is generated from homologous recombination between shuttle vector and provirus vector. Due to the possible recombination between two proviral vectors, wild-type adenovirus may be generated from this process. Therefore, it is critical to isolate a single clone of virus from an individual plaque and/or examine its genomic structure.

Generation and/or propagation of the current adenovirus vectors, which are replication deficient, depend on a unique helper cell line, designated 293, which was transformed from human embryonic kidney cells by Ad5 DNA fragments and constitutively expresses E1 proteins (E1A and/or E1B; Graham et al., 1977). Since the E3 region is dispensable from the adenovirus genome (Jones and Shenk, 1978), the current adenovirus vectors, with the help of 293 cells, carry foreign DNA in either the E1, the D3 and both regions (Graham and Prevec, 1991). Recently, adenoviral vectors comprising deletions in the E4 region have been described (U.S. Pat. No. 5,670,488, incorporated herein by reference).

In nature, adenovirus can package approximately 105% of the wild-type genome (Ghosh-Choudhury et al., 1987), providing capacity for about 2 extra kb of DNA. Combined with the approximately 5.5 kb of DNA that is replaceable in the E1 and/or E3 regions, the maximum capacity of the current adenovirus vector is under 7.5 kb, and/or about 15% of the total length of the vector. More than 80% of the adenovirus viral genome remains in the vector backbone.

Helper cell lines may be derived from human cells such as human embryonic kidney cells, muscle cells, hematopoietic cells and other human embryonic mesenchymal and epithelial cells. Alternatively, the helper cells may be derived from the cells of other mammalian species that are permissive for human adenovirus. Such cells include, e.g., Vero cells and other monkey embryonic mesenchymal and/or epithelial cells. As stated above, the preferred helper cell line is 293.

Recently, Racher et al (1995) disclosed improved methods for culturing 293 cells and/or propagating adenovirus. In one format, natural cell aggregates are grown by inoculating individual cells into 1 liter siliconized spinner flasks (Techne, Cambridge, UK) containing 100-200 ml of medium. Following stirring at 40 rpm, the cell viability is estimated with trypan blue. In another format, Fibra-Cel microcarriers (Bibby Sterlin, Stone, UK) (5 g/l ) is employed as follows. A cell inoculum, resuspended in 5 ml of medium, is added to the carrier (50 ml) in a 250 ml Erlenmeyer flask and/or left stationary, with occasional agitation, for 1 to 4 h. The medium is then replaced with 50 ml of fresh medium and/or shaking initiated. For virus production, cells are allowed to grow to about 80% confluence, after which time the medium is replaced (to 25% of the final volume) and/or adenovirus added at an MOI of 0.05. Cultures are left stationary overnight, following which the volume is increased to 100% and/or shaking commenced for another 72 h.

Other than the requirement that the adenovirus vector be replication defective, and at least conditionally defective, the nature of the adenovirus vector is not believed to be crucial to the successful practice of the invention. The adenovirus may be of any of the 42 different known serotypes and subgroups A-F. Adenovirus type 5 of subgroup C is the preferred starting material in order to obtain the conditional replication-defective adenovirus vector for use in the present invention. This is because Adenovirus type 5 is a human adenovirus about which a great deal of biochemical and genetic information is known, and it has historically been used for most constructions employing adenovirus as a vector.

As stated above, the typical vector according to the present invention is replication defective and will not have an adenovirus E1 region. Thus, it will be most convenient to introduce the transforming construct at the position from which the E1-coding sequences have been removed. However, the position of insertion of the construct within the adenovirus sequences is not critical to the invention. The polynucleotide encoding the gene of interest may also be inserted in lieu of the deleted E3 region in E3 replacement vectors as described by Karlsson et al. (1986) and in the E4 region where a helper cell line and helper virus complements the E4 defect.

Adenovirus growth and/or manipulation is known to those of skill in the art, and/or exhibits broad host range in vitro and in vivo. This group of viruses can be obtained in high titers, e.g., 109 to 1011 plaque-forming units per ml, and they are highly infective. The life cycle of adenovirus does not require integration into the host cell genome. The foreign genes delivered by adenovirus vectors are episomal and, therefore, have low genotoxicity to host cells. No side effects have been reported in studies of vaccination with wild-type adenovirus (Couch et al., 1963; Top et al., 1971), demonstrating their safety and/or therapeutic potential as in vivo gene transfer vectors.

Adenovirus vectors have been used in eukaryotic gene expression (Levrero et al., 1991; Gomez-Foix et al., 1992) and vaccine development (Grunhaus and Horwitz, 1992; Graham and Prevec, 1992). Recently, animal studies suggested that recombinant adenovirus could be used for gene therapy (Stratford-Perricaudet and Perricaudet, 1991a; Stratford-Perricaudet et al., 1991b; Rich et al., 1993). Studies in administering recombinant adenovirus to different tissues include trachea instillation (Rosenfeld et al., 1991; Rosenfeld et al., 1992), muscle injection (Ragot et al., 1993), peripheral intravenous injections (Herz and Gerard, 1993) and/or stereotactic inoculation into the brain (Le Gal La Salle et al., 1993). Recombinant adenovirus and adeno-associated virus (see below) can both infect and transduce non-dividing human primary cells.

AAV Vectors

Adeno-associated virus (AAV) is an attractive vector system for use in the cell transduction of the present invention as it has a high frequency of integration and it can infect nondividing cells, thus making it useful for delivery of genes into mammalian cells, for example, in tissue culture (Muzyczka, 1992) and in vivo. AAV has a broad host range for infectivity (Tratschin et al., 1984; Laughlin et al., 1986; Lebkowski et al., 1988; McLaughlin et al., 1988). Details concerning the generation and use of rAAV vectors are described in U.S. Pat. No. 5,139,941 and/or U.S. Pat. No. 4,797,368, each incorporated herein by reference.

Studies demonstrating the use of AAV in gene delivery include LaFace et al. (1988); Zhou et al. (1993); Flotte et al. (1993); and Walsh et al. (1994). Recombinant AAV vectors have been used successfully for in vitro and/or in vivo transduction of marker genes (Kaplitt et al., 1994; Lebkowski et al., 1988; Samulski et al., 1989; Yoder et al., 1994; Zhou et al., 1994; Hermonat and Muzyczka, 1984; Tratschin et al., 1985; McLaughlin et al., 1988) and genes involved in human diseases (Flotte et al., 1992; Luo et al., 1994; Ohi et al., 1990; Walsh et al., 1994; Wei et al., 1994). Recently, an AAV vector has been approved for phase I human trials for the treatment of cystic fibrosis.

AAV is a dependent parvovirus in that it requires coinfection with another virus (either adenovirus and a member of the herpes virus family) to undergo a productive infection in cultured cells (Muzyczka, 1992). In the absence of coinfection with helper virus, the wild type AAV genome integrates through its ends into human chromosome 19 where it resides in a latent state as a provirus (Kotin et al., 1990; Samulski et al., 1991). rAAV, however, is not restricted to chromosome 19 for integration unless the AAV Rep protein is also expressed (Shelling and Smith, 1994). When a cell carrying an AAV provirus is superinfected with a helper virus, the AAV genome is “rescued” from the chromosome and from a recombinant plasmid, and/or a normal productive infection is established (Samulski et al., 1989; McLaughlin et al., 1988; Kotin et al., 1990; Muzyczka, 1992).

Typically, recombinant AAV (rAAV) virus is made by cotransfecting a plasmid containing the gene of interest flanked by the two AAV terminal repeats (McLaughlin et al., 1988; Samulski et al., 1989; each incorporated herein by reference) and/or an expression plasmid containing the wild type AAV coding sequences without the terminal repeats, for example pIM45 (McCarty et al., 1991; incorporated herein by reference). The cells are also infected and transfected with adenovirus and plasmids carrying the adenovirus genes required for AAV helper function. rAAV virus stocks made in such fashion are contaminated with adenovirus which must be physically separated from the rAAV particles (for example, by cesium chloride density centrifugation). Alternatively, adenovirus vectors containing the AAV coding regions and cell lines containing the AAV coding regions and some and all of the adenovirus helper genes could be used (Yang et al., 1994; Clark et al., 1995). Cell lines carrying the rAAV DNA as an integrated provirus can also be used (Flotte et al., 1995).

Retroviral Vectors

Retroviruses have promise as gene delivery vectors due to their ability to integrate their genes into the host genome, transferring a large amount of foreign genetic material, infecting a broad spectrum of species and cell types and of being packaged in special cell-lines (Miller, 1992).

The retroviruses are a group of single-stranded RNA viruses characterized by an ability to convert their RNA to double-stranded DNA in infected cells by a process of reverse-transcription (Coffin, 1990). The resulting DNA then stably integrates into cellular chromosomes as a provirus and/or directs synthesis of viral proteins. The integration results in the retention of the viral gene sequences in the recipient cell and/or its descendants. The retroviral genome contains three genes, gag, pol, and/or env that code for capsid proteins, polymerase enzyme, and envelope components, respectively. A sequence found upstream from the gag gene contains a signal for packaging of the genome into virions. Two long terminal repeat (LTR) sequences are present at the 5′ and 3′ ends of the viral genome. These contain strong promoter and enhancer sequences and are also required for integration in the host cell genome (Coffin, 1990).

In order to construct a retroviral vector, a nucleic acid encoding a gene of interest is inserted into the viral genome in the place of certain viral sequences to produce a virus that is replication-defective. In order to produce virions, a packaging cell line containing the gag, pol, and env genes but without the LTR and packaging components is constructed (Mann et al., 1983). When a recombinant plasmid containing a cDNA, together with the retroviral LTR and packaging sequences is introduced into this cell line (by calcium phosphate precipitation for example), the packaging sequence allows the RNA transcript of the recombinant plasmid to be packaged into viral particles, which are then secreted into the culture media (Nicolas and Rubenstein, 1988; Temin, 1986; Mann et al., 1983). The media containing the recombinant retroviruses is then collected, optionally concentrated, and used for gene transfer. Retroviral vectors are able to infect a broad variety of cell types. However, integration and/or stable expression require the division of host cells (Paskind et al., 1975).

Concern with the use of defective retrovirus vectors is the potential appearance of wild-type replication-competent virus in the packaging cells. This can result from recombination events in which the intact sequence from the recombinant virus inserts upstream from the gag, pol, env sequence integrated in the host cell genome. However, new packaging cell lines are now available that should greatly decrease the likelihood of recombination (Markowitz et al., 1988; Hersdorffer et al., 1990).

Gene delivery using second generation retroviral vectors has been reported. Kasahara et al. (1994) prepared an engineered variant of the Moloney murine leukemia virus, that normally infects only mouse cells, and modified an envelope protein so that the virus specifically bound to, and infected, human cells bearing the erythropoietin (EPO) receptor. This was achieved by inserting a portion of the EPO sequence into an envelope protein to create a chimeric protein with a new binding specificity.

Specific retroviral vectors useful in the present invention include lentivirus and Vesicular Stomatitis Virus-Indiana.

Other Viral Vectors

Other viral vectors may be employed as expression constructs in the present invention. Vectors derived from viruses such as vaccinia virus (Ridgeway, 1988; Baichwal and Sugden, 1986; Coupar et al., 1988), sindbis virus, cytomegalovirus and/or herpes simplex virus may be employed. They offer several attractive features for various mammalian cells (Friedmann, 1989; Ridgeway, 1988; Baichwal and Sugden, 1986; Coupar et al., 1988; Horwich et al., 1990).

With the recent recognition of defective hepatitis B viruses, new insight was gained into the structure-function relationship of different viral sequences. In vitro studies showed that the virus could retain the ability for helper-dependent packaging and reverse transcription despite the deletion of up to 80% of its genome (Horwich et al., 1990). This suggested that large portions of the genome could be replaced with foreign genetic material. Chang et al. recently introduced the chloramphenicol acetyltransferase (CAT) gene into duck hepatitis B virus genome in the place of the polymerase, surface, and/or pre-surface coding sequences. It was cotransfected with wild-type virus into an avian hepatoma cell line. Culture media containing high titers of the recombinant virus were used to infect primary duckling hepatocytes. Stable CAT gene expression was detected for at least 24 days after transfection (Chang et al., 1991).

In certain further embodiments, the gene therapy vector will be HSV. A factor that makes HSV an attractive vector is the size and organization of the genome. Because HSV is large, incorporation of multiple genes and expression cassettes is less problematic than in other smaller viral systems. In addition, the availability of different viral control sequences with varying performance (temporal, strength, etc.) makes it possible to control expression to a greater extent than in other systems. It also is an advantage that the virus has relatively few spliced messages, further easing genetic manipulations. HSV also is relatively easy to manipulate and/or can be grown to high titers. Thus, delivery is less of a problem, both in terms of volumes needed to attain sufficient MOI and in a lessened need for repeat dosings

Modified Viruses

In still further embodiments of the present invention, the nucleic acids to be delivered are housed within an infective virus that has been engineered to express a specific binding ligand. The virus particle will thus bind specifically to the cognate receptors of the target cell and deliver the contents to the cell. A novel approach designed to allow specific targeting of retrovirus vectors was recently developed based on the chemical modification of a retrovirus by the chemical addition of lactose residues to the viral envelope. This modification can permit the specific infection of hepatocytes via sialoglycoprotein receptors.

Another approach to targeting of recombinant retroviruses was designed in which biotinylated antibodies against a retroviral envelope protein and/or against a specific cell receptor were used. The antibodies were coupled via the biotin components by using streptavidin (Roux et al., 1989). Using antibodies against major histocompatibility complex class I and class II antigens, they demonstrated the infection of a variety of human cells that bore those surface antigens with an ecotropic virus in vitro (Roux et al., 1989).

Other Methods of DNA Delivery

In various embodiments of the invention, DNA is delivered to a cell as an expression construct. In order to effect expression of a gene construct, the expression construct must be delivered into a cell. As described herein, the preferred mechanism for delivery is via viral infection, where the expression construct is encapsidated in an infectious viral particle. However, several non-viral methods for the transfer of expression constructs into cells also are contemplated by the present invention. In one embodiment of the present invention, the expression construct may consist only of naked recombinant DNA and/or plasmids. Transfer of the construct may be performed by any of the methods mentioned which physically and/or chemically permeabilize the cell membrane. Some of these techniques may be successfully adapted for in vivo and/or ex vivo use, as discussed below.

Liposome-Mediated Transfection

In a further embodiment of the invention, the expression construct may be entrapped in a liposome. Liposomes are vesicular structures characterized by a phospholipid bilayer membrane and/or an inner aqueous medium. Multilamellar liposomes have multiple lipid layers separated by aqueous medium. They form spontaneously when phospholipids are suspended in an excess of aqueous solution. The lipid components undergo self-rearrangement before the formation of closed structures and/or entrap water and/or dissolved solutes between the lipid bilayers (Ghosh and Bachhawat, 1991). Also contemplated is an expression construct complexed with Lipofectamine (Gibco BRL). Liposome-mediated nucleic acid delivery and expression of foreign DNA in vitro has been very successful (Nicolau and Sene, 1982; Fraley et al., 1979; Nicolau et al., 1987). Wong et al. (1980) demonstrated the feasibility of liposome-mediated delivery and/or expression of foreign DNA in cultured chick embryo, HeLa and hepatoma cells.

In certain embodiments of the invention, the liposome may be complexed with a hemagglutinating virus (HVJ). This has been shown to facilitate fusion with the cell membrane and/or promote cell entry of liposome-encapsulated DNA (Kaneda et al., 1989). In other embodiments, the liposome may be complexed and/or employed in conjunction with nuclear non-histone chromosomal proteins (HMG-1) (Kato et al., 1991). In yet further embodiments, the liposome may be complexed and/or employed in conjunction with both HVJ and HMG-1. In other embodiments, the delivery vehicle may comprise a ligand and a liposome. Where a bacterial promoter is employed in the DNA construct, it also will be desirable to include within the liposome an appropriate bacterial polymerase.

The inventors contemplate that neu-suppressing gene products can be introduced into cells using liposome-mediated gene transfer. It is proposed that such constructs can be coupled with liposomes and directly introduced via a catheter, as described by Nabel et al. (1990). By employing these methods, the neu-suppressing gene products can be expressed efficiently at a specific site in vivo, not just the liver and spleen cells which are accessible via intravenous injection. Therefore, this invention also encompasses compositions of DNA constructs encoding a neu-suppressing gene product formulated as a DNA/liposome complex and methods of using such constructs.

As described in U.S. Pat. No. 5,641,484, liposomes are particularly well suited for the treatment of HER2/neu-mediated cancer

Preparation of Liposomes

Catatonic liposomes that are efficient transfection reagents for targeting fusion for animal cells can be prepared using the method of Gao et al. (1991). Gao et al. describes a novel catatonic cholesterol derivative that can be synthesized in a single step. Liposomes made of this lipid are reportedly more efficient in transfection and less toxic to treated cells than those made with the reagent Lipofectin. These lipids are a mixture of DC-Chol (“3′(N-(N′N′-dimethylaminoethane)-carbamoyl cholesterol”) and DOPE (“dioleoylphosphatidylethanolamine”). The steps in producing these liposomes are as follows.

DC-Chol is synthesized by a simple reaction from cholesteryl chloroformate and N,N-Dimethylethylenediamine. A solution of cholesteryl chloroformate (2.25 g, 5 mmol in 5 ml dry chloroform) is added dropwise to a solution of excess N,N-Dimethylethylenediamine (2 ml, 18.2 mmol in 3 ml dry chloroform) at 0° C. Following removal of the solvent by evaporation, the residue is purified by recrystallization in absolute ethanol at 4° C. and dried in vacuo. The yield is a white powder of DC-Chol.

Cationic liposomes are prepared by mixing 1.2 μmol of DC-Chol and 8.0 μmol of DOPE in chloroform. This mixture is then dried, vacuum desiccated, and resuspended in 1 ml sterol 20 mM Hepes buffer (pH 7.8) in a tube. After 24 hours of hydration at 4° C., the dispersion is sonicated for 5-10 minutes in a sonicator form liposomes with an average diameter of 150-200 nm.

To prepare a liposome/DNA complex, the inventors use the following steps. The DNA to be transfected is placed in DMEM/F12 medium in a ratio of 15 μg DNA to 50 μl DMEM/F12. DMEM/F12 is then used to dilute the DC-Chol/DOPE liposome mixture to a ratio of 50 μl DMEZM/F12 to 100 μl liposome. The DNA dilution and the liposome dilution are then gently mixed, and incubated at 37° C. for 10 minutes. Following incubation, the DNA/liposome complex is ready for injection.

Liposomal transfection can be via liposomes composed of, for example, phosphatidylcholine (PC), phosphatidylserine (PS), cholesterol (Chol), N-[1-(2,3-dioleyloxy)propyl]-N,N-trimethylammonium chloride (DOTMA), dioleoylphosphatidylethanolamine (DOPE), and/or 3 .beta.[N-(N′N′-dimethylaminoethane)-carbarmoyl cholesterol (DC-Chol), as well as other lipids known to those of skill in the art. Those of skill in the art will recognize that there are a variety of liposomal transfection techniques which will be useful in the present invention. Among these techniques are those described in Nicolau et al., 1987, Nabel et al., 1990, and Gao et al., 1991. In a specific embodiment, the liposomes comprise DC-Chol. More particularly, the inventors the liposomes comprise DC-Chol and DOPE which have been prepared following the teaching of Gao et al. (1991) in the manner described in the Preferred Embodiments Section. The inventors also anticipate utility for liposomes comprised of DOTMA, such as those which are available commercially under the trademark Lipofectin™, from Vical, Inc., in San Diego, Calif.

Liposomes may be introduced into contact with cells to be transfected by a variety of methods. In cell culture, the liposome-DNA complex can simply be dispersed in the cell culture solution. For application in vivo, liposome-DNA complex are typically injected. Intravenous injection allow liposome-mediated transfer of DNA complex, for example, the liver and the spleen. In order to allow transfection of DNA into cells which are not accessible through intravenous injection, it is possible to directly inject the liposome-DNA complexes into a specific location in an animal's body. For example, Nabel et al. teach injection via a catheter into the arterial wall. In another example, the inventors have used intraperitoneal injection to allow for gene transfer into mice.

The present invention also contemplates compositions comprising a liposomal complex. This liposomal complex will comprise a lipid component and a DNA segment encoding a nucleic acid encoding an anti-angiogenic targeting fusion. The nucleic acid encoding the targeting fusion employed in the liposomal complex can be, for example, one which encodes targeting fusions described herein.

The lipid employed to make the liposomal complex can be any of the above-discussed lipids. In particular, DOTMA, DOPE, and/or DC-Chol may form all or part of the liposomal complex. The inventors have had particular success with complexes comprising DC-Chol. In a preferred embodiment, the lipid will comprise DC-Chol and DOPE. While any ratio of DC-Chol to DOPE is anticipated to have utility, it is anticipated that those comprising a ratio of DC-Chol:DOPE between 1:20 and 20:1 will be particularly advantageous. The inventors have found that liposomes prepared from a ratio of DC-Chol:DOPE of about 1:10 to about 1:5 have been useful.

In a specific embodiment, one employs the smallest region needed to enhance retention of targeting fusion in the nucleus of a cell so that one is not introducing unnecessary DNA into cells which receive a targeting fusion gene construct. Techniques well known to those of skill in the art, such as the use of restriction enzymes, will allow for the generation of small regions of targeting fusion. The ability of these regions to inhibit neu can easily be determined by the assays reported in the Examples.

In certain embodiments of the invention, the liposome may be complexed with a hemagglutinatin virus (HVJ). This has been shown to facilitate fusion with the cell membrane and promote cell entry of liposome-encapsulated DNA (Kaneda et al., 1989). In other embodiments, the liposome may be complexed or employed in conjunction with nuclear non-histone chromosomal proteins (HMG-1) (Kato et al., 1991). In yet further embodiments, the liposome may be complexed or employed in conjunction with both HVJ and HMG-1. In that such expression constructs have been successfully employed in transfer and expression of nucleic acid in vitro and in vivo, then they are applicable for the present invention. Where a bacterial promoter is employed in the DNA construct, it also will be desirable to include within the liposome an appropriate bacterial polymerase.

In vivo Treatment of Cancer Via Liposomes with Targeting Fusions

Based on the teachings provided herein, a skilled artisan recognizes that any cell may be treated with at least one targeting fusion, and in particular embodiments, any cancer cell may be treated with such. For example, in some embodiments the nature of the treated cell is irrespective of being HER2/neu-positive or HER2/neu-negative.

U.S. Pat. No. 5,641,484, incorporated in its entirety by reference herein, teaches that liposome-mediated direct gene transfer techniques can be employed to obtain suppression of HER2/neu-overexpressing human cancer cells in living host. The exemplary protocol for described therein was as follows. Female nude mice (5-6 weeks old) were given intraperitoneal injections of SK-OV-3 cells (2×10⁶/100 μl). SK-OV-3 cells are human ovarian cancer cells that have been shown to grow within the peritoneal cavity of nude mice. After five days, the mice were given intraperitoneal injections of various compounds. Some mice were injected with the therapeutic DNA alone, some were injected with liposome/therapeutic DNA complex prepared in the manner described above, and some were injected with liposome/mutant therapeutic DNA complex. 200 μl of a given compound was injected into a given mouse. After the initial injections, injections were repeated every seven days throughout the life of the mouse.

The results described therein indicate that liposome-mediated gene transfer can inhibit HER2/neu-overexpressing human ovarian cancer cell growth. Therefore, it is predictable that liposome-mediated targeting fusion gene therapy may serve as a powerful therapeutic agent for HER-2 neu-overexpressing human ovarian cancers by direct targeting of targeting fusion at the HER-2 neu-oncogene.

Liposomal Transfection with Targeting Fusion to Treat Humans

Based on the results of the in vivo animal studies described in U.S. Pat. No. 5,641,484, those of skill in the art will understand and predict the enormous potential for human treatment of HER2/neu-mediated cancers with an anti-angiogenic targeting fusion complexed to liposomes. Clinical studies to demonstrate these effects are contemplated. Those of skill in the art will recognize that the best treatment regimens for using targeting fusions to suppress cancers can be straightforwardly determined. This is not a question of experimentation, but rather one of optimization, which is routinely conducted in the medical arts. In vivo studies in nude mice provide a starting point from which to begin to optimize the dosage and delivery regimes. The frequency of injection is initially once a week, as was done in the mice studies described in U.S. Pat. No. 5,641,484. However, this frequency might be optimally adjusted from one day to every two weeks to monthly, depending upon the results obtained from the initial clinical trials and the needs of a particular patient. Human dosage amounts can initially be determined by extrapolating from the amount of targeting fusion used in mice, approximately 15 μg of plasmid DNA per 50 g body weight. Based on this, a 50 kg woman would require treatment with 15 mg of DNA per dose. Of course, this dosage amount may be adjusted upward or downward, as is routinely done in such treatment protocols, depending on the results of the initial clinical trials and the needs of a particular patient. These clinical trials are anticipated to show utility of targeting fusions for the treatment of HER2/neu-overexpressing cancers in humans. Dosage and frequency regimes will initially be based on the data obtained from in vivo animal studies, as is done frequently in the art

Electroporation

In certain embodiments of the present invention, the expression construct is introduced into the cell via electroporation. Electroporation involves the exposure of a suspension of cells and/or DNA to a high-voltage electric discharge.

Transfection of eukaryotic cells using electroporation has been quite successful. Mouse pre-B lymphocytes have been transfected with humankappa-immunoglobulin genes (Potter et al., 1984), and/or rat hepatocytes have been transfected with the chloramphenicol acetyltransferase gene (Tur-Kaspa et al., 1986) in this manner.

Calcium Phosphate and/or DEAE-Dextran

I other embodiments of the present invention, the expression construct is introduced to the cells using calcium phosphate precipitation. HumanKB cells have been transfected with adenovirus 5 DNA (Graham and Van Der Eb, 1973) using this technique. Also in this manner, mouse L(A9), mouse C127, CHO, CV-1, BHK, NIH3T3 and/or HeLa cells were transfected with a neomycin marker gene (Chen and Okayama, 1987), and/or rat hepatocytes were transfected with a variety of marker genes (Rippe et al., 1990).

In another embodiment, the expression construct is delivered into the cell using DEAE-dextran followed by polyethylene glycol. In this manner, reporter plasmids were introduced into mouse myeloma and/or erythroleukemia cells (Gopal, 1985).

Particle Bombardment

Another embodiment of the invention for transferring a naked DNA expression construct into cells may involve particle bombardment. This method depends on the ability to accelerate DNA-coated microprojectiles to a high velocity allowing them to pierce cell membranes and/or enter cells without killing them (Klein et al., 1987). Several devices for accelerating small particles have been developed. One such device relies on a high voltage discharge to generate an electrical current, which in turn provides the motive force (Yang et al., 1990). The microprojectiles used have consisted of biologically inert substances such as tungsten and/or gold beads.

Direct Microinjection and/or Sonication Loading

Further embodiments of the present invention include the introduction of the expression construct by direct microinjection and/or sonication loading. Direct microinjection has been used to introduce nucleic acid constructs into Xenopus oocytes (Harland and Weintraub, 1985), and/or LTK-fibroblasts have been transfected with the thymidine kinase gene by sonication loading (Fechheimer et al., 1987).

Adenoviral Assisted Transfection

In certain embodiments of the present invention, the expression construct is introduced into the cell using adenovirus assisted transfection. Increased transfection efficiencies have been reported in cell systems using adenovirus coupled systems (Kelleher and Vos, 1994; Cotten et al., 1992; Curiel, 1994).

Pharmaceutical Preparations

Pharmaceutical compositions of the present invention comprise an effective amount of one or more forms of an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, such as an anti-angiogenesis targeting fusion and/or additional agent dissolved or dispersed in a pharmaceutically acceptable carrier or excipient. The phrases “pharmaceutical or pharmacologically acceptable” refers to molecular entities and compositions that do not produce an adverse, allergic or other untoward reaction when administered to an animal, such as, for example, a human, as appropriate. The preparation of an pharmaceutical composition that contains at least one targeting fusion form or additional active ingredient will be known to those of skill in the art in light of the present disclosure, as exemplified by Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, incorporated herein by reference. Moreover, for animal (e.g., human) administration, it will be understood that preparations should meet sterility, pyrogenicity, general safety and purity standards as required by FDA Office of Biological Standards.

As used herein, “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, surfactants, antioxidants, preservatives (e.g., antibacterial agents, antifungal agents), isotonic agents, absorption delaying agents, salts, preservatives, drugs, drug stabilizers, binders, excipients, disintegration agents, lubricants, sweetening agents, flavoring agents, dyes, such like materials and combinations thereof, as would be known to one of ordinary skill in the art (see, for example, Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, pp. 1289-1329, incorporated herein by reference). Except insofar as any conventional carrier is incompatible with the active ingredient, its use in the therapeutic or pharmaceutical compositions is contemplated.

The targeting fusion form may comprise different types of carriers depending on whether it is to be administered in solid, liquid or aerosol form, and whether it need to be sterile for such routes of administration as injection. The present invention can be administered intravenously, intradermally, intraarterially, intraperitoneally, intralesionally, intracranially, intraarticularly, intraprostaticaly, intrapleurally, intratracheally, intranasally, intravitreally, intravaginally, rectally, topically, intratumorally, intramuscularly, intraperitoneally, subcutaneously, intravesicularlly, mucosally, intrapericardially, orally, topically, locally, using aerosol, injection, infusion, continuous infusion, localized perfusion bathing target cells directly, via a catheter, via a lavage, in cremes, in lipid compositions (e.g., liposomes), or by other method or any combination of the forgoing as would be known to one of ordinary skill in the art (see, for example, Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, incorporated herein by reference).

The actual dosage amount of a composition of the present invention administered to an animal patient can be determined by physical and physiological factors such as body weight, severity of condition, the type of disease being treated, previous or concurrent therapeutic interventions, idiopathy of the patient and on the route of administration. The practitioner responsible for administration will, in any event, determine the concentration of active ingredient(s) in a composition and appropriate dose(s) for the individual subject.

In certain embodiments, pharmaceutical compositions may comprise, for example, at least about 0.1% of an active compound. In other embodiments, the an active compound may comprise between about 2% to about 75% of the weight of the unit, or between about 25% to about 60%, for example, and any range derivable therein. In other non-limiting examples, a dose may also comprise from about 1 microgram/kg/body weight, about 5 microgram/kg/body weight, about 10 microgram/kg/body weight, about 50 microgram/kg/body weight, about 100 microgram/kg/body weight, about 200 microgram/kg/body weight, about 350 microgram/kg/body weight, about 500 microgram/kg/body weight, about 1 milligram/kg/body weight, about 5 milligram/kg/body weight, about 10 milligram/kg/body weight, about 50 milligram/kg/body weight, about 100 milligram/kg/body weight, about 200 milligram/kg/body weight, about 350 milligram/kg/body weight, about 500 milligram/kg/body weight, to about 1000 mg/kg/body weight or more per administration, and any range derivable therein. In non-limiting examples of a derivable range from the numbers listed herein, a range of about 5 mg/kg/body weight to about 100 mg/kg/body weight, about 5 microgram/kg/body weight to about 500 milligram/kg/body weight, etc., can be administered, based on the numbers described above.

In any case, the composition may comprise various antioxidants to retard oxidation of one or more component. Additionally, the prevention of the action of microorganisms can be brought about by preservatives such as various antibacterial and antifungal agents, including but not limited to parabens (e.g., methylparabens, propylparabens), chlorobutanol, phenol, sorbic acid, thimerosal or combinations thereof.

The targeting fusion form may be formulated into a composition in a free base, neutral or salt form. Pharmaceutically acceptable salts, include the acid addition salts, e.g., those formed with the free amino groups of a proteinaceous composition, or which are formed with inorganic acids such as for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric or mandelic acid. Salts formed with the free carboxyl groups can also be derived from inorganic bases such as for example, sodium, potassium, ammonium, calcium or ferric hydroxides; or such organic bases as isopropylamine, trimethylamine, histidine or procaine.

In embodiments where the composition is in a liquid form, a carrier can be a solvent or dispersion medium comprising but not limited to, water, ethanol, polyol (e.g., glycerol, propylene glycol, liquid polyethylene glycol, etc.), lipids (e.g., triglycerides, vegetable oils, liposomes) and combinations thereof. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin; by the maintenance of the required particle size by dispersion in carriers such as, for example liquid polyol or lipids; by the use of surfactants such as, for example hydroxypropylcellulose; or combinations thereof such methods. In many cases, it will be preferable to include isotonic agents, such as, for example, sugars, sodium chloride or combinations thereof.

In other embodiments, one may use eye drops, nasal solutions or sprays, aerosols or inhalants in the present invention. Such compositions are generally designed to be compatible with the target tissue type. In a non-limiting example, nasal solutions are usually aqueous solutions designed to be administered to the nasal passages in drops or sprays. Nasal solutions are prepared so that they are similar in many respects to nasal secretions, so that normal ciliary action is maintained. Thus, in preferred embodiments the aqueous nasal solutions usually are isotonic or slightly buffered to maintain a pH of about 5.5 to about 6.5. In addition, antimicrobial preservatives, similar to those used in ophthalmic preparations, drugs, or appropriate drug stabilizers, if required, may be included in the formulation. For example, various commercial nasal preparations are known and include drugs such as antibiotics or antihistamines.

In certain embodiments the targeting fusion form is prepared for administration by such routes as oral ingestion. In these embodiments, the solid composition may comprise, for example, solutions, suspensions, emulsions, tablets, pills, capsules (e.g., hard or soft shelled gelatin capsules), sustained release formulations, buccal compositions, troches, elixirs, suspensions, syrups, wafers, or combinations thereof. Oral compositions may be incorporated directly with the food of the diet. Preferred carriers for oral administration comprise inert diluents, assimilable edible carriers or combinations thereof. In other aspects of the invention, the oral composition may be prepared as a syrup or elixir. A syrup or elixir, and may comprise, for example, at least one active agent, a sweetening agent, a preservative, a flavoring agent, a dye, a preservative, or combinations thereof.

In certain preferred embodiments an oral composition may comprise one or more binders, excipients, disintegration agents, lubricants, flavoring agents, and combinations thereof. In certain embodiments, a composition may comprise one or more of the following: a binder, such as, for example, gum tragacanth, acacia, cornstarch, gelatin or combinations thereof; an excipient, such as, for example, dicalcium phosphate, mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate or combinations thereof; a disintegrating agent, such as, for example, corn starch, potato starch, alginic acid or combinations thereof; a lubricant, such as, for example, magnesium stearate; a sweetening agent, such as, for example, sucrose, lactose, saccharin or combinations thereof; a flavoring agent, such as, for example peppermint, oil of wintergreen, cherry flavoring, orange flavoring, etc.; or combinations thereof the foregoing. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, carriers such as a liquid carrier. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. For instance, tablets, pills, or capsules may be coated with shellac, sugar or both.

Additional formulations which are suitable for other modes of administration include suppositories. Suppositories are solid dosage forms of various weights and shapes, usually medicated, for insertion into the rectum, vagina or urethra. After insertion, suppositories soften, melt or dissolve in the cavity fluids. In general, for suppositories, traditional carriers may include, for example, polyalkylene glycols, triglycerides or combinations thereof. In certain embodiments, suppositories may be formed from mixtures containing, for example, the active ingredient in the range of about 0.5% to about 10%, and preferably about 1% to about 2%.

Sterile injectable solutions are prepared by incorporating the active compounds in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and/or the other ingredients. In the case of sterile powders for the preparation of sterile injectable solutions, suspensions or emulsion, the preferred methods of preparation are vacuum-drying or freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered liquid medium thereof. The liquid medium should be suitably buffered if necessary and the liquid diluent first rendered isotonic prior to injection with sufficient saline or glucose. The preparation of highly concentrated compositions for direct injection is also contemplated, where the use of DMSO as solvent is envisioned to result in extremely rapid penetration, delivering high concentrations of the active agents to a small area.

The composition must be stable under the conditions of manufacture and storage, and preserved against the contaminating action of microorganisms, such as bacteria and fungi. It will be appreciated that endotoxin contamination should be kept minimally at a safe level, for example, less that 0.5 ng/mg protein.

In particular embodiments, prolonged absorption of an injectable composition can be brought about by the use in the compositions of agents delaying absorption, such as, for example, aluminum monostearate, gelatin or combinations thereof.

In a particular embodiment of the present invention, a composition is utilized wherein the composition is an anti-angiogenic targeting fusion, the expression of which is regulated at least in part by a promoter comprising one such as is described in U.S. Provisional Patent Application Ser. No. 60/377,672, filed May 5, 2002, and entitled “BIPARTITE T-CELL FACTOR (TCF)-RESPONSIVE PROMOTER” and in U.S. Nonprovisional Patent Application Ser. No 10/429,802, filed May 5, 2003 under Express Mail number EU 110397859US, both of which are incorporated by reference herein in their entirety, and wherein said fusion is comprised with a liposome, such as DC-Chol, DOTMA, and the like.

EXAMPLES

The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

Example 1 Exemplary Materials and Methods

Immunoblotting: The endostatin, endostatin-cytosine deaminase (endo-CD), and endostatin-interleukin-12 (endo-IL12) containing plasmid was used to transfect 293T cells using the cationic liposome method. After transfection, the medium was replaced by serum free medium. Then, after a 24 hr incubation, the supernatant was collected and western blotted with anti-endostatin antibody.

ELISA: COS-7 cells were transfected with plasmids encoding either, Endostatin-IL2 or Endostatin-GM-CSF using cationic liposome. After transfection, the medium was replaced wtih serum free medium and the supoernatant was harvested and subjected to ELISA to detect the endostatin protein.

Example 2 Expression of Antiangiogenic-Therapeutic/Diagnostic Fusion Genes

FIG. 1 shows that following production of fusion protein, antiangiogenic-therapeutic/diagnostic fusion protein could be detected. In FIG. 1A, there is an anti-endostatin antibody Western blot of supernatants collected from 293 cells. Eighteen KD endostatin(□), 58 KD endostatin-CD (

), and 93 KD endo-IL12(←) could be detected. FIG. 1B illustrates that by using ELISA kit (specific for endostatin), endostatin-IL2 and endostatin-GM-CSF fusion proteins could also be detected and quantified.

Example 3 Exemplary Materials and Methods for Characterizing Antiangiogenic and Therapeutic/Diagnostic Functions of the Fusion Proteins

Endothelial tube assay: Matrigel (Collaborative Biomolecules, Bedford, Mass.) was added (50 μl) to each well of a 96-well plate and allowed to polymerize. A suspension of 5,000 human umbilical endothelial cells (HUVEC) in EGM-2 medium without antibiotic was passed into each well coated with matrigel. The cells were treated with supernatants collected from different plasmid (endostatin, endostatin-CD, and CD) transfected 293T cells. All assays were performed in triplicate. Cell were incubated for 12-24 hr at 37° C. and viewed using a microscope. The cells were then photographed. Five fields were viewed, and tubes were counted and averaged.

Migration assay: The inhibitory effect of endostatin on VEGF-induced chemotaxis was tested on HUVECs using the Boyden chamber assay. After trypsinizing, washing, and diluting cells in M199 medium containing 0.5% FBS, 10,000 cells were seeded on the upper chamber wells, together with supernatant collected from 293T transfected with different plasmid (endostatin, endostatin-CD, and CD). M199 medium containing 2% FBS plus 10 ng/ml VEGF was placed in the lower chamber as a chemotactant. The cell-containing compartments were separated from the chemotactant with polycarbonate filter of 8 um pore size. The chamber was incubated at 37° C. for 6-8 hr. After discarding the non-migrated cells and washing the upper wells with PBS, the filters were scraped with a plastic blade, fixed in 4% formaldehyde in PBS, stained with DAPI fluorescent stain and placed on a glass slide. By using a fluorescent high power field, several independent homogenous images were recorded. Five fields were viewed, and tubes were counted and averaged. All assays were performed in triplicate.

MTT assay: The cytotoxic effect of 5FU converted from 5FC reacted with cytosine deaminase(CD) was 293T cells using MTT assay. The inventors use different plasmid(endostatin, endostatin-CD, and CD) to transfect 293T cells and incubated 12-14 hrs. After trypsinizing, washing, and diluting cells in DMEM medium containing 2% FBS plus different concentration of 5FU or 5FC, 5,000 cells were seeded on each well of 96-well plate. Then the plate was incubated at 37° C. for 3-4 days. The inventors add 20 μl of MTT solution and incubate for 2 hr, then 100 μl of lysing solution was added to each well and incubated overnight night. The light absorbance was measured at 570 nm on the following day.

Green fluorescence expression: The endostatin-GFP containing plasmid was used to transfect 293T cells with the same method. After 36 hr incubation, the GFP fluorescence was observed under fluorescent microscope.

NSF60 (GM-CSF dependent) Cell proliferation assay: To quantify the biological activity of the Endostatin-GM-CSF, the factor dependent cell line NSF60 was used. NSF60 cells were incubated with condition medium from COS-7 cells transfecte with either control plasmid, plasmid encoding Endostatin-GM-CSF, or two different concentrations of recombinant GM-CSF. After 48 hr of incubation, NSF60 proliferation was determined by measuring the activity of dehydrogenase-enzyme as marker for the biological activity, using 2 mg/ml Cell Titer 96TM MTS Reagent Powder (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) (Promega, USA) and 0.92 mg/ml Phenazine methosulfate (Sigma, USA). The OD₄₀₅ values reflected the cell numbers.

Example 4 Fusion Proteins Possess both Antiangiogenic and Therapeutic/Diagnostic Functions

FIG. 2 shows that, in comparison to endostatin, endo-CD fusion protein exhibit similar antiangiogenic effects in endothelial tube (FIGS. 2A-2D) and migration (FIGS. 2E-2H) assays. As supernatant collected from endostatin gene transfection, the supernatant from endostatin-CD fusion gene demonstrated inhibitory effect on HUVEC cell tube formation (FIGS. 2A, 2B, and 2C) and cell migration (FIGS. 2E, 2F, and 2G). In FIGS. 2D and 2H, five fields were viewed, and the tubes or migrated cells were counted and averaged.

FIG. 3 illustrates that therapeutic or diagnostic functions of fusion genes could be detected. In FIGS. 3A and 3B, a MTT assay is provided. As different concentrations of 5FU or 5FC with CD gene transfection were provided, endo-CD gene transfection demonstrated the killing effect on 293T cells. In FIG. 3C, green fluorescent protein expression in 293T cells transfected with Endo-GFP fusion gene could be detected by fluorescent microscope. In FIG. 3D, the cell proliferation of NSF60 could be stimulated by conditional medium from COS-7 transfected by Endostatin-GM-CSF plasmid. OD₄₀₅ values of NSF60 incubated with conditional medium from COS-7 transfected by Endostatin-GM-CSF plasmid was slightly better than those cells incubated with 15.6 nM recombinant GM-CSF protein. Therefore, the protein encoded by Endostatin-GM-CSF plasmid exhibited GM-CSF function, as evidenced by proliferation of GM-CSF dependent NSF60.

Example 5 Exemplary Materials and Methods for Tumor-Specific Targeting Effect of Antiangiogenic-Therapeutic/Diagnostic Fusion Proteins

In vitro Endothelial Cell Targeting

To demonstrate the specific targeting effect of antiangiogenic/therapeutic or antiangiogenic/diagnostic fusion gene, the inventors seeded the previously established 293T endostatin-GFP stable clone to a 10 cm plate. At the same time, different cell lines (MDA-231 breast cancer cell, mouse endothelial cell-SVEC, and human endothelial cell-HUVEC) were seeded to a 4-chamber plate. After the cells attached, the inventors put the 4-well plate into the 10 cm plate and added enough medium to cover all the wells. After 48 hr incubation, the 4-well plate was washed with PBS and the green fluorescence was observed under the fluorescent microscope.

In vivo Tumor Targeting

The inventors subcutaneously injected 2×10⁵ B16 cells from parental cell line or endostatin-GFP stable clone to 7-9-week-old B57 mice. Each mice bears two injection sites. In experimental group, the inventors injected B16 parental cells to one site and B16 endostatin-GFP cells to the other. In control group, both sites received the tumor cells from B16 parental cells. After 14 days, the tumors were harvested and fixed. The inventors use anti-GFP antibody for immunohistochemical staining.

Example 6 Tumor Specific Targeting Effect of Antiangiogenic-Therapeutic/Diagnostic Fusion Proteins

FIG. 4 shows that endostatin-GFP specifically targets to endothelial cells. After being incubated with 293T endostatin-GFP stable clone for 48 hr, a lot of green fluorescent signals could be detected in SVEC mouse endothelial cell (E) but not in MDA-231 breast cancer cells (B).

FIG. 5 GFP signal was detected in the vascular wall of B-16 parental tumors. FIG. 5A demonstrates an experimental group. Diffuse GFP signal was found in tumor of B-16 endostatin-GFP stable cell lines. FIG. 5B shows in contra-lateral tumor to A (from B-16 parental cell lines), GFP signal was found in blood vessel wall (

). In FIG. 5C, there is no GFP signals could be detected in tumors from bilateral B-16 parental cell lines in control group.

Example 7 Exemplary Materials and Methods for Animal Models of

Endostatin-GFP Inhibit both Regional and Distant Tumor Growth

Endostatin-GFP plasmid was used to transfect B16 melanoma cell. After the stable clones were established, the inventors subcutaneously injected 2×10⁵ B16 cells from parental cell line or endostatin-GFP stable clone to 7-9-week-old B57 mice. The animals were divided into two groups. Each group contained 10 mice, and every mice had two injection sites. In the experimental group, the inventors injected B16 parental cells to one site and B16 endostatin-GFP cells to the other. In the control group, both sites received the tumor cells from B16 parental cells. The tumors were measured and calculated on the 14th day. Volume±S.D. is plotted.

Superior Anticancer Effect of Fusion Proteins Against Regional Tumor

B16F10 melanoma tumor model—Either 1×10⁶ cells or 2.5×10⁵ cells of B16-F10 were injected subcutaneously into the right flank of 6-7 week-old C57/BL6 immunocompetent female mice. Four days after inoculation, tumors (about 5 mm in diameter) were directly injected with different plasmid DNA encoding Luciferase, Endostatin, IL12, or Endostatin-IL12 and cationic liposome complexes (in 100 μl saline). The treatment was repeated three times a day for every four days. Seventeen days after the tumor was inoculated, the tumor sizes of each experimental group were measured.

CT-26 colon cancer model—CT-26 colon cancer cells (2×10⁵) were injected subcutaneously into 7-9-week-old B57CL6 mice on right flank. Simultaneously, another set of CT-26 melanoma cells (2×10⁵) were injected subcutaneously into the left flank of the mice. Four days after the tumor was challenged, different plasmids containing either Luciferase (Luc), endostatin (Endo), interleukin-12 (IL-12), or Endo-IL12 fusion gene were intratumorally injected into the left flank CT-26 tumor. This procedure was repeated twice a week, and the tumor size was measured every two days. The size of distant tumor on the right flank was calculated and plotted over the treatment period.

Example 8 Animal Models of Antiangiogenic-Therapeutic/Diagnostic Fusion Proteins

FIG. 6 shows stable clone-expressed endostatin-GFP inhibits contra-lateral and local tumor growth. In a control group, all the tumors were measured and averaged together. The tumors in an experimental group were measured and averaged according to their cell lines (B16 parental melanoma cell line or endostatin-GFP stable clones).

FIG. 7 shows that endo-IL12 has a superior anticancer effect compared to IL12 or endostatin alone in different independent animal studies. In FIG. 7A, there is intratumoral gene therapy against B16F10 tumor. Endostatin-IL12 demonstrates the most significant anti-cancer effect on subcutaneous xenograft B16-F10 melanoma cancer compared to both endostatin and IL12 genes. In FIG. 7B, there is similar intratumoral gene therapy as in FIG. 7A against B16F10 tumor, except the original distant tumor was challenged at 2×10⁵ cell. The endo-IL12 still showed better therapeutic effect than IL12 and endostatin alone, as provided in FIG. 7C.

Example 9 Materials and Methods for Anticancer Effect of Fusion Proteins Against Distant Tumor

Ex vivo transfection: B16-F10 melanoma cells (2×10⁵) were injected subcutaneously into 7-9-week-old B57CL6 mice on right flank on day 0. All groups contained 10 mice. The inventors used the different plasmids containing either Luciferase (Luc), endostatin (Endo), cytosine deaminase (CD) and endostatin-CD (endo-CD), antiangiogenic deletion mutant of tumstatin (tum5), interleukin-12 (IL-12), or Tum5-IL12 fusion gene to transfect the B16F10 melanoma cells. After transfection, these melanoma cells were harvested and injected into the left flank of the mice in a different group on day 1. This procedure was repeated 3 more times on day 4, 7, 10. Distant tumors on the right flank were measured, and the volume was calculated and plotted over the treatment period.

Stable clones: B16-F10 melanoma cells (2×10⁵) were injected subcutaneously into 7-9-week-old B57CL6 mice on the right flank. Two days after, 2×10⁵ of endostatin, IL12 or endo-IL12 expressing stable clones of B16F10 cancer cells were injected subcutaneously on the left flank. The stable clone cancer cells were repeat injected twice a week. The size of distant tumor on the right flank was measured every two days.

Example 10 Superior Anticancer Effect of Fusion Proteins Against Distant Tumor

FIG. 8 demonstrates a superior anticancer effect on distant tumor of fusion proteins expressed by either stable clones or ex vivo transfection. In FIG. 8A, ex vivo treatment of endostatin-CD fusion gene of antiangio-chemotherapy showed better inhibitory effect on contra-lateral tumor growth. (Endo: endostatin; CD: cytosine deaminase; Endo-CD: fusion gene). FIG. 8B shows that ex vivo treatment of Tum5-IL12 fusion gene of antiangio-immunotherapy showed better tumor inhibitory effect on distant tumor (Tum5: tumstatin antiangiogenic deletion mutant, IL12: interleukin-12, Tum5-IL12: fusion gene). FIG. 8C provides that distant CT26 colon cancer growths were most significantly inhibited by Endo-IL12 gene therapy. Various genes were injected into CT26 tumor sites distant from the measured tumors, which were not treated with direct injection of genes. FIG. 8D shows stable line treatment of endostatin-IL12 against distant tumor. Endo-IL12 showed better anti-cancer effect than other therapeutic proteins.

Example 11 Significance of the Results

The results demonstrated above show that antiangiogenic fusion genes are useful as gene therapy and diagnostic reagents, as evidenced by results from studies provided herein. In FIG. 1, the fusion gene could lead to expression of fusion proteins, which were detected by immunoblotting and ELISA. As shown in FIG. 2 and FIG. 3, the fusion proteins are functional and possess both antiangiogenic properties as well as the functions attributable at least in part to the attached proteins. In these functional assays, fusion protein Endostatin-CD, for example, could inhibit angiogenesis to a similar extent of wild type Endostatin, as shown by endothelial tube formation and migration assays. In addition, the therapeutic/diagnostic proteins attached to the exemplary endostatin still functions as in their wild type form. Endostatin-GFP exhibits green fluorescence. Endostatin-GM-CSF could induce proliferation of NSF60 cells, whose growth is GM-CSF dependent. Endostatin-CD could convert non-toxic 5-FC to toxic 5-FU, thereby killing both 293T and HUVEC (human umbilical vascular endothelial cell) cells.

In both in vitro (FIG. 4) and pathological studies (FIG. 5), Endostatin-GFP is shown to be endothelial cell-specific. In FIG. 4, only endothelial cells (SVEC) exhibit GFP signal when incubated with conditional medium containing Endostatin-GFP. In FIG. 5, Endostatin-GFP is able to travel from Endostatin-GFP stable clone tumor (FIG. 5A) to distant parental B16-F10 melanoma cells. Endostatin-GFP is detected by anti-GFP antibody (FIG. 5B). In contrast, when B16-F10 tumor-bearing mice were not inoculated with Endostatin-GFP stable clone tumor, the parental cells did not show GFP signal (FIG. 5C). In other words, the endostatin component of the fusion protein Endostatin-GFP could lead GFP protein to the distant tumor blood vessel sites. Thus, the use of antiangiogenic proteins (endostatin, in this exemplary case) to deliver otherwise non-tumor blood vessel-specific proteins (such as, for example, GFP) to the tumor site is demonstrated. In addition, Endostatin-GFP serves as a diagnostic tool in other embodiments, since fluorescent signal emitted by GFP could be detected, and endostatin could target new blood vessels of tumor.

Lastly, the fusion genes as well as encoded fusion proteins are useful as therapeutic reagents. The inventors have used fusion genes, for example Endostatin-IL12, showing superior anticancer effects than either endostatin or IL12 alone, to treat both melanoma- (FIG. 7A and FIG. 7B) and colon cancer-bearing (FIG. 7C) mice. The fusion proteins encoded by these genes are also effective as protein therapeutic reagents as shown in another animal study (FIG. 8), where tumor cells ex vivo treated with (FIG. 8A and FIG. 8B), or established tumor injected with fusion genes (FIG. 8C), or stable clones (FIG. 8D) served as a “protein factory” and the secreted proteins were able to inhibit distant tumor growth.

Example 12 Ex vivo Testing of an Angiogenesis Inhibitor Coupled to a Therapeutic or Diagnostic Agent

One useful biological property for an anti-cancer therapeutic is its ability to reduce tumorigenicity in vivo. To test the possibly, in some embodiments, anti-tumor activity of an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent not utilized in studies provided herein may be demonstrated. For example, an ex vivo tumorigenicity assay may be performed in a nude mice cancer model. As exemplary cancer cell lines, human breast cancer cell lines MCF-7 and prostate cancer cell line PC-3 may be transfected with a fusion gene delivered by SN liposome in culture plates. Twenty-four hours later, the treated cells may be carefully harvested and inoculated into the mammary fat pads (mfp) (for MCF-7) or subcutaneous connective tissue (for PC-3) of nude mice. For example, four million cells may be inoculated for MCF-7 and one million cells for PC-3. Empty vector pcDNA3-transfected cells can be used as a control. The inoculated tumor size may be measured weekly.

This “ex vivo test” bypasses the gene delivery problems in vivo and shows that under the optimal gene delivery condition, tumor cells with fusion genes with antiangiogenic properties may have less tumor growth ability than controls.

Example 13 In vivo Testing of Angiogenesis Inhibitor Coupled to a Therapeutic or Diagnostic Agent

In some embodiments, an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, such as an antiangiogenic fusion gene product, described herein or prepared by those of skill in the art based on the teachings provided herein, is used in the following in vivo study. Mice with established tumors are treated with the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent, such as by injection, and shown to provide inhibition of tumor growth in mice compared with proper controls.

A systemic gene therapy approach for breast cancer may be utilized, consisting of, for example, a nonviral gene delivery system (SN) and a fusion gene. The SN-fusion gene may be systemically administered and shown to inhibit the growth and metastasis of, for example, human breast cancer cells implanted in nude mice and, in some embodiments, prolongs the life span of the treated animals.

Obviously, methods disclosed herein have proven useful for specific fusion genes in the context of the invention. Following the teachings provided herein, one of skill in the art can prepare and test any number of fusion genes for anti-angiogenesis activity, anti-cell proliferative activity, antitumor activity, pro-apoptotic activity, or a combination thereof.

Example 14 Testing of Exemplary Angiogenesis Inhibitor Coupled to a Therapeutic or Diagnostic Agent

An angiogenesis inhibitor coupled to a therapeutic or diagnostic agent as it relates to anti-tumor activity is tested in an animal study, such as cell lines, cell culture, and/or models in addition to or other than those described in the preceding Examples. In general embodiments of the present invention, fusion genes, for example, are delivered by a vector, such as a liposome, adenoviral vector, or combination thereof, into nude mice models for their anti-tumor activity. Once the anti-tumor activity is demonstrated, potential toxicity is further examined using immunocompetent mice, followed by clinical trials.

In a specific embodiment, the preferential growth inhibitory activity of antiangiogenic fusion genes is tested in at least one animal. Briefly, and for example, cancer cell lines are administered into mammary fat-pad of nude mice to generate a breast xenografted model. Any cancer cell is within the scope of the present invention irrespective of its genotype or expression levels (such as, for example, whether it is HER-2/neu-positive or HER-2/neu-negative). In a specific embodiment, HER-2/neu overexpressing breast cancer cell lines (such as, for example, SKBR3 and/or MDA-MB361) are utilized, such as for testing. After the tumors reach a particular size, the fusion gene and, in some embodiments, the control, is administered into the mouse, such as, for example, intravenously injected in an admixture with an acceptable carrier, such as liposomes. The tumor sizes and survival curve from these treatments are compared and statistically analyzed.

In some embodiments of the present invention, a mouse animal model is utilized to study targeting anti-angiogenic fusion gene products. In one specific embodiment, a bilateral melanoma or colon tumor model is utilized. In another embodiment, a one-sided intratumoral gene therapy protocol is utilized. In another embodiment, wherein a suicide therapeutic gene is utilized in the targeting fusion polypeptide, the model is administered intraperitoneally a prodrug (such as, for example, 5FC) following delivery of the suicide therapeutic gene. In some embodiments, contralateral tumor size is evaluated for a tumor targeting effect. In addition to suicide gene therapy using, for example, endostatin-cytosine deaminase with 5-FC administered as a prodrug, similar approaches are also used for endostatin-IL12. Ipsilateral tumor size may also be evaluated for chemotherapy effect, in some embodiments.

Example 15 Preparation of Additional Angiogenesis Inhibitors Coupled to a Therapeutic or Diagnostic Agent

Based on the data in previous Examples and the teachings elsewhere in the specification, in addition to the knowledge in the art, a skilled artisan would be motivated and capable of generating an additional fusion angiogenesis inhibitor coupled to a therapeutic or diagnostic agent and, furthermore, would be able to determine the usefulness in the context of the invention using methodology disclosed herein.

Example 16 Testing of Additional Angiogenesis Inhibitors Coupled to a Therapeutic or Diagnostic Agent

Once an angiogenesis inhibitor coupled to a therapeutic or diagnostic agent other than the exemplary embodiments disclosed herein is created, testing using a cell culture in a relevant cell line(s) may be performed, such as described herein. Furthermore, testing of, for example, the antiangiogenic fusion gene products may be performed, such as by using FACS analysis. Also, testing of the additional antiangiogenic fusion gene products using ex vivo systems or in vivo systems as described herein may be employed, in specific embodiments.

Example 17 Clinical Trials

This example is concerned with the development of human treatment protocols using the angiogenesis inhibitor coupled to a therapeutic or diagnostic agents. In specific embodiments, the angiogenesis inhibitor coupled to a therapeutic or diagnostic agent is an antiangiogenic fusion gene product including protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, alone or in combination with other drugs. In a specific embodiment, the other drugs are also useful for treatment of angiogenesis, such as for tumor inhibition. In a specific embodiment, the drug is useful for treating cancer. The antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, and anti-cancer drug treatment will be of use in the clinical treatment of various cancers. Such treatment will be particularly useful tools in anti-tumor therapy, for example, in treating patients with ovarian, breast, prostate, pancreatic, brain, colon, and lung cancers that are resistant to conventional chemotherapeutic regimens.

The various elements of conducting a clinical trial, including patient treatment and monitoring, will be known to those of skill in the art in light of the present disclosure. The following information is being presented as a general guideline for use in establishing the antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, in clinical trials.

Patients with advanced, metastatic breast, epithelial ovarian carcinoma, pancreatic, colon, or other cancers chosen for clinical study will typically be at high risk for developing the cancer, will have been treated previously for the cancer which is presently in remission, or will have failed to respond to at least one course of conventional therapy. In an exemplary clinical protocol, patients may undergo placement of a Tenckhoff catheter, or other suitable device, in the pleural or peritoneal cavity and undergo serial sampling of pleural/peritoneal effusion. Typically, one will wish to determine the absence of known loculation of the pleural or peritoneal cavity, creatinine levels that are below 2 mg/dl, and bilirubin levels that are below 2 mg/dl. The patient should exhibit a normal coagulation profile.In regard to the antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, and other anti-cancer drug administration, a Tenckhoff catheter, or alternative device may be placed in the pleural cavity or in the peritoneal cavity, unless such a device is already in place from prior surgery. A sample of pleural or peritoneal fluid can be obtained, so that baseline cellularity, cytology, LDH, and appropriate markers in the fluid (CEA, CA15-3, CA 125, PSA, p38 (phosphorylated and un-phosphorylated forms), Akt (phosphorylated and un-phosphorylated forms) and in the cells (antiangiogenic fusion proteins, peptides or polypeptides or nucleic acids encoding the same) may be assessed and recorded.

In the same procedure, the antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, may be administered alone or in combination with the other anti-cancer drug. The administration may be in the pleural/peritoneal cavity, directly into the tumor, or in a systemic manner. The starting dose may be 0.5 mg/kg body weight. Three patients may be treated at each dose level in the absence of grade>3 toxicity. Dose escalation may be done by 100% increments (0.5 mg, 1 mg, 2 mg, 4 mg) until drug related grade 2 toxicity is detected. Thereafter dose escalation may proceed by 25% increments. The administered dose may be fractionated equally into two infusions, separated by six hours if the combined endotoxin levels determined for the lot of the antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, and the lot of anti-cancer drug exceed 5 EU/kg for any given patient.

The antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, and/or the other anti-cancer drug combination, may be administered over a short infusion time or at a steady rate of infusion over a 7 to 21 day period. The antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the antiangiogenic fusion protein, peptide, or polypeptides, infusion may be administered alone or in combination with the anti-cancer drug and/or emodin like tyrosine kinase inhibitor. The infusion given at any dose level will be dependent upon the toxicity achieved after each. Hence, if Grade II toxicity was reached after any single infusion, or at a particular period of time for a steady rate infusion, further doses should be withheld or the steady rate infusion stopped unless toxicity improved. Increasing doses of the antiangiogenic fusion protein, peptide, or polypeptide or a nucleic acid encoding the mutant protein, peptide, or polypeptides, in combination with an anti-cancer drug will be administered to groups of patients until approximately 60% of patients show unacceptable Grade III or IV toxicity in any category. Doses that are ⅔ of this value could be defined as the safe dose.

Physical examination, tumor measurements, and laboratory tests should, of course, be performed before treatment and at intervals of about 3-4 weeks later. Laboratory studies should include CBC, differential and platelet count, urinalysis, SMA-12-100 (liver and renal function tests), coagulation profile, and any other appropriate chemistry studies to determine the extent of disease, or determine the cause of existing symptoms. Also appropriate biological markers in serum should be monitored e.g. CEA, CA 15-3, p38 (phosphorylated and non-phopshorylated forms) and Akt (phosphorylated and non-phosphorylated forms), p185, etc.

To monitor disease course and evaluate the anti-tumor responses, it is contemplated that the patients should be examined for appropriate tumor markers every 4 weeks, if initially abnormal, with twice weekly CBC, differential and platelet count for the 4 weeks; then, if no myelosuppression has been observed, weekly. If any patient has prolonged myelosuppression, a bone marrow examination is advised to rule out the possibility of tumor invasion of the marrow as the cause of pancytopenia. Coagulation profile shall be obtained every 4 weeks. An SMA-12-100 shall be performed weekly. Pleural/peritoneal effusion may be sampled 72 hours after the first dose, weekly thereafter for the first two courses, then every 4 weeks until progression or off study. Cellularity, cytology, LDH, and appropriate markers in the fluid (CEA, CA15-3, CA 125, ki67 and Tunel assay to measure apoptosis, Akt) and in the cells (Akt) may be assessed. When measurable disease is present, tumor measurements are to be recorded every 4 weeks. Appropriate radiological studies should be repeated every 8 weeks to evaluate tumor response. Spirometry and DLCO may be repeated 4 and 8 weeks after initiation of therapy and at the time study participation ends. An urinalysis may be performed every 4 weeks.

Clinical responses may be defined by acceptable measure. For example, a complete response may be defined by the disappearance of all measurable disease for at least a month. Whereas a partial response may be defined by a 50% or greater reduction of the sum of the products of perpendicular diameters of all evaluable tumor nodules or at least 1 month with no tumor sites showing enlargement. Similarly, a mixed response may be defined by a reduction of the product of perpendicular diameters of all measurable lesions by 50% or greater with progression in one or more sites.

REFERENCES

All patents and publications mentioned in the specification are indicative of the level of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

PATENTS

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Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. 

1. A method comprising contacting intratumorally a cancer cell in a tumor of a subject with an expression vector comprising a nucleic acid encoding a polypeptide comprising an endostatin polypeptide linked to a cytosine deaminase polypeptide, said method further comprising providing 5-fluorocytosine to the subject, wherein expression of the polypeptide results in inhibition of tumor growth.
 2. The method of claim 1, wherein the subject is a human.
 3. The method of claim 1, wherein the cancer cell is from head and neck cancer, ovarian cancer, thyroid cancer, oral cancer, prostate cancer, melanoma, colon cancer, breast cancer, angioma, sarcoma, lung cancer, brain cancer, pancreatic cancer, liver cancer, bladder cancer, or gastrointestinal cancer.
 4. The method of claim 1, wherein the nucleic acid is comprised in a plasmid, a retroviral vector, an adenoviral vector, an adeno-associated viral vector, or a liposome.
 5. The method of claim 1, wherein the nucleic acid is dispersed in a pharmacologically acceptable excipient.
 6. A method of inhibiting a tumor comprising intratumorally administering to a subject having a tumor autologous tumor cells transfected with an expression vector comprising a nucleic acid encoding a polypeptide comprising an endostatin polypeptide linked to cytosine deaminase, said method further comprising providing 5-fluorocytosine to the subject, wherein expression of the polypeptide results in inhibition of tumor growth.
 7. A method comprising administering to a subject having a tumor autologous tumor cells transfected with an expression vector comprising nucleic acid encoding a polypeptide comprising an endostatin polypeptide linked to a cytosine deaminase polypeptide, said method further comprising providing 5-fluorocytosine to the subject, wherein expression of the polypeptide results in inhibition of tumor growth.
 8. A method comprising contacting a cancer cell in a tumor of a subject with an expression vector comprising a nucleic acid encoding a polypeptide comprising an endostatin polypeptide linked to cytosine deaminase, said method further comprising providing 5-fluorocytosine to the subject, wherein expression of the polypeptide results in inhibition of tumor growth, wherein the vector is administered to the subject intravenously or subcutaneously in a nucleic acid/liposomal complex. 